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/zbar/index.ts

@@ -43,7 +43,7 @@ export interface ZBarOptions {
  * Requires Cordova plugin: `cordova-plugin-cszbar`. For more info, please see the [zBar plugin docs](https://github.com/tjwoon/csZBar).
  *
  * @usage
- * ```
+ * ```typescript
  * import { ZBar, ZBarOptions } from '@ionic-native/z-bar';
  *
  * constructor(private zbar: ZBar) { }
@@ -51,7 +51,7 @@ export interface ZBarOptions {
  * ...
  *
  * let ZBarOptions = {
- *       flash: "off",
+ *       flash: 'off',
  *       drawSight: false
  *     };
  *