Add Ponyfills (#1692)

Co-Authored-By: Sindre Sorhus <sindresorhus@gmail.com>

readme.md

@@ -135,6 +135,7 @@
 	- [Observables](https://github.com/sindresorhus/awesome-observables#readme)
 	- [npm scripts](https://github.com/RyanZim/awesome-npm-scripts#readme) - Task runner.
 	- [30 Seconds of Code](https://github.com/30-seconds/30-seconds-of-code#readme) - Code snippets you can understand in 30 seconds.
+	- [Ponyfills](https://github.com/Richienb/awesome-ponyfills#readme) - Like polyfills but without overriding native APIs.
 - [Swift](https://github.com/matteocrippa/awesome-swift#readme) - Apple's compiled programming language that is secure, modern, programmer-friendly, and fast.
 	- [Education](https://github.com/hsavit1/Awesome-Swift-Education#readme)
 	- [Playgrounds](https://github.com/uraimo/Awesome-Swift-Playgrounds#readme)