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/shake/index.ts

@@ -38,6 +38,6 @@ export class Shake extends IonicNativePlugin {
     successIndex: 0,
     errorIndex: 2
   })
-  startWatch(sensitivity?: number): Observable<any> {return; }
+  startWatch(sensitivity?: number): Observable<any> { return; }
 
 }