style(): unify docs and spacing (#1448)

* 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.

src/@ionic-native/plugins/app-update/index.ts

@@ -19,7 +19,7 @@ import { Injectable } from '@angular/core';
  *
  * Then use the following code:
  *
- * ```
+ * ```typescript
  * import { AppUpdate } from '@ionic-native/app-update';
  *
  * constructor(private appUpdate: AppUpdate) {
@@ -28,8 +28,6 @@ import { Injectable } from '@angular/core';
  *    this.appUpdate.checkAppUpdate(updateUrl);
  *
  * }
- *
- *
  * ```
  *
  * The plugin will compare the app version and update it automatically if the API has a newer version to install.
@@ -53,4 +51,3 @@ export class AppUpdate extends IonicNativePlugin {
   })
   checkAppUpdate(updateUrl: string): Promise<any> { return; }
 }
-