add strong recommendation for ts playground

Author: swyxio

README.md

@@ -109,8 +109,9 @@
 ## Prerequisites
 
 1. good understanding of [React](https://reactjs.org)
-2. familiarity with [TypeScript Types](https://www.typescriptlang.org/docs/handbook/basic-types.html) ([2ality's guide](http://2ality.com/2018/04/type-notation-typescript.html) is helpful)
+2. familiarity with [TypeScript Basic Types](https://www.typescriptlang.org/docs/handbook/basic-types.html) ([2ality's guide](http://2ality.com/2018/04/type-notation-typescript.html) is helpful)
 3. having read [the TypeScript section in the official React docs](https://reactjs.org/docs/static-type-checking.html#typescript).
+4. having read [the React section of the new TypeScript playground](http://www.typescriptlang.org/play/index.html?jsx=2&esModuleInterop=true&e=181#example/typescript-with-react) (optional: also step through the 40+ examples under [the playground's](http://www.typescriptlang.org/play/index.html) Examples section)
 
 This guide will always assume you are starting with the latest TypeScript version. Notes for older versions will be in expandable `<details>` tags.
 
@@ -1679,6 +1680,7 @@ Believe it or not, we have only barely introduced TypeScript here in this cheats
 
 It is worth mentioning some resources to help you get started:
 
+- Step through the 40+ examples under [the playground's](http://www.typescriptlang.org/play/index.html) Examples section, written by @Orta
 - Anders Hejlsberg's overview of TS: https://www.youtube.com/watch?v=ET4kT88JRXs
 - Marius Schultz: https://blog.mariusschulz.com/series/typescript-evolution with an [Egghead.io course](https://egghead.io/courses/advanced-static-types-in-typescript)
 - Basarat's Deep Dive: https://basarat.gitbooks.io/typescript/