Update docs for new naming convention

Author: Will Morgan

README.md

@@ -1,26 +1,23 @@
 silverstripe-googlemapfield
 ==============
 
-Lets you record a precise location using latitude/longitude fields to a DataObject.
+Lets you record a precise location using latitude/longitude/zoom fields to a DataObject.
 
 Displays a map using the Google Maps API. The user may then choose where to place the marker; the landing coordinates are then saved.
 
 You can also search for locations using the search box, which uses the Google Maps Geocoding API.
 
-Use the 2.4 branch for SilverStripe 2.4.
-
-
 ### Usage
 
 ##### `__construct` options
 
 |Option|Default|Description|
 |------|-------|-----------|
-|`fieldNames`|See `GoogleMapField::$defaults`|A map of what your object's latitude/longitude fields are. Defaults to `Lat` for `lat` and `Lng` for `lng`.|
+|`field_names`|See `GoogleMapField.yml`'s `default_options.field_names`|A map of field names to save the map data into your object.|
 
 ##### `Field` options
 
 |Option|Default|Description|
 |------|-------|-----------|
 |`coords`|Your object's latitude and longitude|The intial coordinates of the map - note: this is not the default value if no object exists|
-|`map`|Zoom of 8, map type of ROADMAP|A [google.maps.MapOptions](https://developers.google.com/maps/documentation/javascript/reference?csw=1#MapOptions) object|
+|`map`|Zoom of 14, map type of ROADMAP|A [google.maps.MapOptions](https://developers.google.com/maps/documentation/javascript/reference?csw=1#MapOptions) object|