docs(readme): remove beta notes

Author: danielsogl

README.md

@@ -11,13 +11,11 @@ Ionic Native wraps plugin callbacks in a Promise or Observable, providing a comm
 Run following command to install Ionic Native in your project.
 
 ```bash
-npm install @ionic-native/core@beta --save
+npm install @ionic-native/core --save
 ```
 
 You also need to install the Ionic Native package for each plugin you want to add. Please see the [Ionic Native documentation](https://ionicframework.com/docs/native/) for complete instructions on how to add and use the plugins.
 
-**NOTE: to use Ionic Native v5, you must use the `@beta` tag when installing any NPM package.**
-
 ## Documentation
 
 For the full Ionic Native documentation, please visit [https://ionicframework.com/docs/native/](https://ionicframework.com/docs/native/).