Improvements on documentation (#340)

* Improvements on documentation and some refactor

* ts | js -> typescript (docs)

src/plugins/facebook.ts

@@ -69,8 +69,8 @@ import { Cordova, Plugin } from './plugin';
  * For tracking events, see `logEvent` and `logPurchase`.
  *
  * @usage
- * ```js
- * import {Facebook} from 'ionic-native';
+ * ```typescript
+ * import { Facebook } from 'ionic-native';
  *
  *
  *
@@ -98,7 +98,7 @@ export class Facebook {
   /**
    * Login to Facebook to authenticate this app.
    *
-   * ```ts
+   * ```typescript
    * {
    *   status: "connected",
    *   authResponse: {
@@ -245,7 +245,9 @@ export class Facebook {
     url: string,
     picture: string
   }): Promise<any> { return; }
+
 }
+
 export interface FacebookLoginResponse {
   status: string;
   authResponse: {