docs(spotify): Spotify Auth & Firebase Crashlytics

src/@ionic-native/plugins/firebase-crashlytics/index.ts

@@ -16,7 +16,7 @@ import { Cordova, IonicNativePlugin, Plugin } from '@ionic-native/core';
  * ...
  *
  *
- * const crashlytics = this.firebaseCrashlytics.initialize();
+ * const crashlytics = this.firebaseCrashlytics.initialise();
  * crashlytics.logException('my caught exception');
  *
  * ```

src/@ionic-native/plugins/spotify-auth/index.ts

@@ -56,7 +56,7 @@ export interface AuthorizationData {
  *
  * @usage
  * ```typescript
- * import { SpotifyAuth } from '@ionic-native/spotify-auth';
+ * import { SpotifyAuth } from '@ionic-native/spotify-auth/ngx';
  *
  * // [...]
  *
@@ -82,7 +82,7 @@ export interface AuthorizationData {
  *
  * // [...]
  *
- * this.spotifyAuth.forget().then(() => console.log("We're logged out!"));
+ * this.spotifyAuth.forget();
  *
  * // [...]
  * ```