Add extension https://github.com/WoofWoofCodes/pxt-javascript-extras #210
Description
GitHub repo: https://github.com/WoofWoofCodes/pxt-javascript-extras
Forum post: https://forum.makecode.com/t/making-an-extension-for-every-javascript-exclusive-feature-i-can-think-of/36766?u=unsignedarduino
Demo: [INSERT DEMO LINK - NOT REQUIRED]
Description: [INSERT SHORT DESCRIPTION THAT IS SIMILAR TO CURRENT DESCRIPTIONS OF EXTENSIONS - REQUIRED]