message: docs(readme): Improve clarity of library installation and usage
diff: @@ -69,6 +69,8 @@ Observable::of(1,2,3)::map(x => x + '!!!'); // etc
  ### CommonJS via npm
  +To install this library for CommonJS (CJS) usage, use the following command:
  +
  ```sh
  npm install rxjs
  ```
  @@ -112,6 +114,8 @@ To install this library via [npm](https://www.npmjs.org) **version 3**, use the
  npm install @reactivex/rxjs
  ```
  +This will include CJS/Global builds and can be used for all module types.
  +
  If you are using npm **version 2** before this library has achieved a stable version, you need to specify the library version explicitly:
  ```sh
  