📚 docs: Remove useless warning about runtime.

Author: make-github-pseudonymous-again

doc/manual/usage.md

@@ -1,17 +1,6 @@
 # Usage
 
-> :warning: Depending on your environment, the code may require
-> `regeneratorRuntime` to be defined, for instance by importing
-> [regenerator-runtime/runtime](https://www.npmjs.com/package/regenerator-runtime).
-
-First, require the polyfill at the entry point of your application
-```js
-require( 'regenerator-runtime/runtime' ) ;
-// or
-import 'regenerator-runtime/runtime.js' ;
-```
-
-Then, import the library where needed
+Import the library where needed
 ```js
 const operator = require( '@aureooms/js-operator' ) ;
 // or