docs(api): document API

Author: nivekcode

README.md

@@ -14,6 +14,9 @@
   - [Download the module](#download-the-module)
   - [Apply the directive](#apply-the-directive)
   - [React on changes](#react-on-changes)
+- [API](#api)
+  - [Inputs](#inputs)
+  - [Outputs](#outputs)
 
 # Getting started
 ## Download the module
@@ -98,3 +101,20 @@ at the top of your page. In this case you need to scroll once you drag an elemen
 The *scrollSpeed* property accepts a number and allows you to specify the scrolling speed.
 
 [Check out the scroll demo](https://kreuzerk.github.io/ng-sortgrid/scrolling)
+
+# API
+
+## Inputs
+| Value             | Description                                                                                                                                    | Default|
+|-------------------|------------------------------------------------------------------------------------------------------------------------------------------------|--------|
+| ngSortGridGroup: string | Groups a grid - avoids that items from one grid can be dragged to another grid                                                         |undefined|
+| ngSortGridItems: any[] | Sort grid items. Pass down a list of all your items. This list is needed to enable the sorting feature.|undefined|
+| autoScroll: boolean | Flag to enable autoscrolling|false|
+| scrollPointTop: number | Custom top scrollpoint in pixels|if autoscroll is applied we start scrolling if we pass the top border|
+| scrollPointBottom: number | Custom bottom scrollpoint in pixels|if autoscroll is applied we start scrolling if we pass the bottom border|
+| scrollSpeed: number | Scrollspeed, the higher the value, the higher we scroll.|50 - only applies if autoscrolling is on|
+
+## Outputs
+| Value             | Description                                                                                                                                    | Default|
+|-------------------|------------------------------------------------------------------------------------------------------------------------------------------------|--------|
+| sorted: EventEmitter<NgsgOrderChange<T> | Emits an event after we sorted the items, each event is of type NgsgOrderChange. The NgsgOrderChange contains the previousOrder and the currentOrder                                                         |undefined|

projects/ng-sortgrid/src/lib/ngsg-item.directive.ts

@@ -28,10 +28,10 @@ const selector = '[ngSortgridItem]';
 @Directive({selector})
 export class NgsgItemDirective implements OnInit, OnChanges, AfterViewInit, OnDestroy {
   @Input() ngSortGridGroup = 'defaultGroup';
-  @Input() ngSortGridItems;
-  @Input() scrollPointTop;
-  @Input() scrollPointBottom;
-  @Input() scrollSpeed;
+  @Input() ngSortGridItems: any[];
+  @Input() scrollPointTop: number;
+  @Input() scrollPointBottom: number;
+  @Input() scrollSpeed: number;
   @Input() autoScroll = false;
 
   @Output() sorted = new EventEmitter<NgsgOrderChange<any>>();