message: docs(README): update examples and usage explanation
  Update examples and usage explanation to be more inline with the current version of RxJS
diff: @@ -46,18 +46,19 @@ By contributing or commenting on issues in this repository, whether you've read
  npm install rxjs
  ```
  -To import only what you need by patching (this is useful for size-sensitive bundling):
  +It's recommended to pull in the Observable creation methods you need directly from `'rxjs'` as shown below with `range`. And you can pull in any operator you need from one spot, under `'rxjs/operators'`.
  ```js
  -import { Observable, Subject, ReplaySubject, from, of, range } from 'rxjs';
  -import { map, filter, switchMap } from 'rxjs/operators';
  +import { range } from 'rxjs';
  +import { map, filter } from 'rxjs/operators';
  -range(1, 200)
  - .pipe(filter(x => x % 2 === 1), map(x => x + x))
  - .subscribe(x => console.log(x));
  +range(1, 200).pipe(
  + filter(x => x % 2 === 1),
  + map(x => x + x)
  +).subscribe(x => console.log(x));
  ```
  -Alternatively, you can use the built-in `pipe` method on Observables. See [pipeable operators](https://github.com/ReactiveX/rxjs/blob/master/doc/pipeable-operators.md) for more information.
  +Here, we're using the built-in `pipe` method on Observables to combine operators. See [pipeable operators](https://github.com/ReactiveX/rxjs/blob/master/doc/pipeable-operators.md) for more information.
  ### CommonJS via npm
  @@ -70,12 +71,13 @@ npm install rxjs
  (Note: destructuring available in Node 8+)
  ```js
  -const { Observable, Subject, ReplaySubject, from, of, range } = require('rxjs');
  -const { map, filter, switchMap } = require('rxjs/operators');
  +const { range } = require('rxjs');
  +const { map, filter } = require('rxjs/operators');
  -range(1, 200)
  - .pipe(filter(x => x % 2 === 1), map(x => x + x))
  - .subscribe(x => console.log(x));
  +range(1, 200).pipe(
  + filter(x => x % 2 === 1),
  + map(x => x + x)
  +).subscribe(x => console.log(x));
  ```
  ### CDN
  @@ -87,19 +89,20 @@ https://unpkg.com/rxjs/bundles/rxjs.umd.min.js
  The global namespace for rxjs is `rxjs`:
  ```js
  -const { Observable, Subject, ReplaySubject, from, of, range } = rxjs;
  -const { map, filter, switchMap } = rxjs.operators;
  +const { range } = rxjs;
  +const { map, filter } = rxjs.operators;
  -range(1, 200)
  - .pipe(filter(x => x % 2 === 1), map(x => x + x))
  - .subscribe(x => console.log(x));
  +range(1, 200).pipe(
  + filter(x => x % 2 === 1),
  + map(x => x + x)
  +).subscribe(x => console.log(x));
  ```
  ## Goals
  - Smaller overall bundles sizes
  - Provide better performance than preceding versions of RxJS
  -- To model/follow the [Observable Spec Proposal](https://github.com/zenparsing/es-observable) to the observable.
  +- To model/follow the [Observable Spec Proposal](https://github.com/zenparsing/es-observable) to the observable
  - Provide more modular file structure in a variety of formats
  - Provide more debuggable call stacks than preceding versions of RxJS
  