feat(native-ringtones): add Native Ringtones plugin (#1488)

* typo(barcode-scanner): fixe circle lint error

* typo(docs):  Unified the documentations

In some plugins the typescript markup was missing.
I also unified the console.log string from console.log("hello") to console.log('Hello') so any plugin page look the same.

* initial commit

Added wrapper

* Added usage guide

* Added parms

src/@ionic-native/plugins/native-ringtones/index.ts

@@ -0,0 +1,59 @@
+import { Cordova, Plugin, IonicNativePlugin } from '@ionic-native/core';
+import { Injectable } from '@angular/core';
+
+/**
+ * @beta
+ * @name Native Ringtones
+ * @description
+ * The plugin helps get the native ringtones list on Android or IOS devices.
+ * And you can also use this plugin to play or stop the native ringtones and custom ringtones(added in the www folder).
+ *
+ * @usage
+ * ```
+ * import { NativeRingtones } from '@ionic-native/native-ringtones';
+ *
+ *
+ * constructor(private ringtones: NativeRingtones) { }
+ *
+ * ...
+ * this.ringtones.getRingtone().then((ringtones) => { console.log(ringtones); });
+ *
+ * this.ringtones.playRingtone('assets/ringtones/sound_1.caf');
+ *
+ * this.ringtones.stopRingtone('assets/ringtones/sound_1.caf');
+ *
+ * ```
+ */
+@Plugin({
+  pluginName: 'native-ringtones',
+  plugin: 'cordova-plugin-native-ringtones',
+  pluginRef: 'cordova.plugins.NativeRingtones',
+  repo: 'https://github.com/TongZhangzt/cordova-plugin-native-ringtones',
+  platforms: ['Android', 'iOS']
+})
+@Injectable()
+export class NativeRingtones extends IonicNativePlugin {
+
+  /**
+   * Get the ringtone list of the device
+   * @return {Promise<any>} Returns a promise that resolves when ringtones found successfully
+   */
+  @Cordova()
+  getRingtone(): Promise<any> { return; }
+
+  /**
+   * This function starts playing the ringtone
+   * @param {string} ringtoneUri The path to the ringtone file
+   * @return {Promise<any>} Returns a promise
+   */
+  @Cordova()
+  playRingtone(ringtoneUri: string): Promise<any> { return; }
+
+  /**
+   * This function stops playing the ringtone
+   * @param {string} ringtoneUri The path to the ringtone file
+   * @return {Promise<any>} Returns a promise
+   */
+  @Cordova()
+  stopRingtone(ringtoneUri: string): Promise<any> { return; }
+}