adding support for geocoder language parameter (#201)

* adding support for geocoder language param

* Refactor options passed to internal Geocoder class

- made options.geocoder dynamic, accepting only query parameters from the Geocoding API
- removed placeholder option in favor of placeholderOrigin and placeholderDestination
- added top level options flyTo, zoom, placeholderOrigin and placeholderDestination

* Fix tests in Geocoder and generate docs for API.md

Author: Kayla Bauhaus

API.md

@@ -23,21 +23,25 @@ The Directions control
 
 **Parameters**
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
-    -   `options.styles` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Override default layer properties of the [directions source](https://github.com/mapbox/mapbox-gl-directions/blob/master/src/directions_style.js). Documentation for each property are specified in the [Mapbox GL Style Reference](https://www.mapbox.com/mapbox-gl-style-spec/).
-    -   `options.accessToken` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Required unless `mapboxgl.accessToken` is set globally (optional, default `null`)
-    -   `options.api` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Override default routing endpoint url
-    -   `options.interactive` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Enable/Disable mouse or touch interactivity from the plugin (optional, default `true`)
-    -   `options.profile` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Routing profile to use. Options: `mapbox/driving-traffic`, `mapbox/driving`, `mapbox/walking`, `mapbox/cycling` (optional, default `"mapbox/driving-traffic"`)
-    -   `options.alternatives` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Whether to enable alternatives. (optional, default `false`)
-    -   `options.congestion` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Whether to enable congestion along the route line. (optional, default `false`)
-    -   `options.unit` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Measurement system to be used in navigation instructions. Options: `imperial`, `metric` (optional, default `"imperial"`)
-    -   `options.compile` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)** Provide a custom function for generating instruction, compatible with osrm-text-instructions. (optional, default `null`)
-    -   `options.geocoder` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Pass options available to mapbox-gl-geocoder as [documented here](https://github.com/mapbox/mapbox-gl-geocoder/blob/master/API.md#mapboxglgeocoder).
-    -   `options.controls` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-        -   `options.controls.inputs` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Hide or display the inputs control. (optional, default `true`)
-        -   `options.controls.instructions` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Hide or display the instructions control. (optional, default `true`)
-        -   `options.controls.profileSwitcher` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Hide or display the default profile switch with options for traffic, driving, walking and cycling. (optional, default `true`)
+-   `options` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+    -   `options.styles` **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Override default layer properties of the [directions source](https://github.com/mapbox/mapbox-gl-directions/blob/master/src/directions_style.js). Documentation for each property are specified in the [Mapbox GL Style Reference](https://www.mapbox.com/mapbox-gl-style-spec/).
+    -   `options.accessToken` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Required unless `mapboxgl.accessToken` is set globally (optional, default `null`)
+    -   `options.api` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Override default routing endpoint url (optional, default `"https://api.mapbox.com/directions/v5/"`)
+    -   `options.interactive` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Enable/Disable mouse or touch interactivity from the plugin (optional, default `true`)
+    -   `options.profile` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Routing profile to use. Options: `mapbox/driving-traffic`, `mapbox/driving`, `mapbox/walking`, `mapbox/cycling` (optional, default `"mapbox/driving-traffic"`)
+    -   `options.alternatives` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Whether to enable alternatives. (optional, default `false`)
+    -   `options.congestion` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Whether to enable congestion along the route line. (optional, default `false`)
+    -   `options.unit` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Measurement system to be used in navigation instructions. Options: `imperial`, `metric` (optional, default `"imperial"`)
+    -   `options.compile` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** Provide a custom function for generating instruction, compatible with osrm-text-instructions. (optional, default `null`)
+    -   `options.geocoder` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Accepts an object containing the query parameters as [documented here](https://www.mapbox.com/api-documentation/#search-for-places).
+    -   `options.controls` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
+        -   `options.controls.inputs` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Hide or display the inputs control. (optional, default `true`)
+        -   `options.controls.instructions` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Hide or display the instructions control. (optional, default `true`)
+        -   `options.controls.profileSwitcher` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Hide or display the default profile switch with options for traffic, driving, walking and cycling. (optional, default `true`)
+    -   `options.zoom` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** If no bbox exists from the geocoder result, the zoom you set here will be used in the flyTo. (optional, default `16`)
+    -   `options.placeholderOrigin` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** If set, this text will appear as the placeholder attribute for the origin input element. (optional, default `"Choose a starting place"`)
+    -   `options.placeholderDestination` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** If set, this text will appear as the placeholder attribute for the destination input element. (optional, default `"Choose destination"`)
+    -   `options.flyTo` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** If false, animating the map to a selected result is disabled. (optional, default `true`)
 
 **Examples**
 
@@ -71,15 +75,15 @@ Turn on or off interactivity
 
 **Parameters**
 
--   `state` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** sets interactivity based on a state of `true` or `false`.
+-   `state` **[Boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** sets interactivity based on a state of `true` or `false`.
 
 Returns **[MapboxDirections](#mapboxdirections)** this
 
 ### getOrigin
 
 Returns the origin of the current route.
 
-Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** origin
+Returns **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** origin
 
 ### setOrigin
 
@@ -88,15 +92,15 @@ to have run.
 
 **Parameters**
 
--   `query` **([Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)> | [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))** An array of coordinates [lng, lat] or location name as a string.
+-   `query` **([Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)> | [String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String))** An array of coordinates [lng, lat] or location name as a string.
 
 Returns **[MapboxDirections](#mapboxdirections)** this
 
 ### getDestination
 
 Returns the destination of the current route.
 
-Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** destination
+Returns **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** destination
 
 ### setDestination
 
@@ -105,7 +109,7 @@ to have run.
 
 **Parameters**
 
--   `query` **([Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)> | [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))** An array of coordinates [lng, lat] or location name as a string.
+-   `query` **([Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)> | [String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String))** An array of coordinates [lng, lat] or location name as a string.
 
 Returns **[MapboxDirections](#mapboxdirections)** this
 
@@ -122,8 +126,8 @@ Add a waypoint to the route. _Note:_ calling this method requires the
 
 **Parameters**
 
--   `index` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** position waypoint should be placed in the waypoint array
--   `waypoint` **([Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)> | Point)** can be a GeoJSON Point Feature or [lng, lat] coordinates.
+-   `index` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** position waypoint should be placed in the waypoint array
+-   `waypoint` **([Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)> | Point)** can be a GeoJSON Point Feature or [lng, lat] coordinates.
 
 Returns **[MapboxDirections](#mapboxdirections)** this;
 
@@ -135,8 +139,8 @@ to have run.
 
 **Parameters**
 
--   `index` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** indexed position of the waypoint to update
--   `waypoint` **([Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)> | Point)** can be a GeoJSON Point Feature or [lng, lat] coordinates.
+-   `index` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** indexed position of the waypoint to update
+-   `waypoint` **([Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)> | Point)** can be a GeoJSON Point Feature or [lng, lat] coordinates.
 
 Returns **[MapboxDirections](#mapboxdirections)** this;
 
@@ -146,15 +150,15 @@ Remove a waypoint from the route.
 
 **Parameters**
 
--   `index` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** position in the waypoints array.
+-   `index` **[Number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)** position in the waypoints array.
 
 Returns **[MapboxDirections](#mapboxdirections)** this;
 
 ### getWaypoints
 
 Fetch all current waypoints in a route.
 
-Returns **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)** waypoints
+Returns **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)** waypoints
 
 ### removeRoutes
 
@@ -168,13 +172,13 @@ Subscribe to events that happen within the plugin.
 
 **Parameters**
 
--   `type` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** name of event. Available events and the data passed into their respective event objects are:-   **clear** `{ type: } Type is one of 'origin' or 'destination'`
+-   `type` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** name of event. Available events and the data passed into their respective event objects are:-   **clear** `{ type: } Type is one of 'origin' or 'destination'`
     -   **loading** `{ type: } Type is one of 'origin' or 'destination'`
     -   **profile** `{ profile } Profile is one of 'driving', 'walking', or 'cycling'`
     -   **origin** `{ feature } Fired when origin is set`
     -   **destination** `{ feature } Fired when destination is set`
     -   **route** `{ route } Fired when a route is updated`
     -   **error** \`{ error } Error as string
--   `fn` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)** function that's called when the event is emitted.
+-   `fn` **[Function](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function)** function that's called when the event is emitted.
 
 Returns **[MapboxDirections](#mapboxdirections)** this;