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/mixpanel/index.ts

@@ -9,7 +9,7 @@ declare var mixpanel: any;
  * Cordova Plugin that wraps Mixpanel SDK for Android and iOS
  *
  * @usage
- * ```
+ * ```typescript
  * import { Mixpanel, MixpanelPeople } from '@ionic-native/mixpanel';
  *
  * constructor(private mixpanel: Mixpanel, private mixpanelPeople: MixpanelPeople) { }