docs: add Discord Server to README (electron#25751)

README.md

@@ -4,6 +4,7 @@
 [![CircleCI Build Status](https://circleci.com/gh/electron/electron/tree/master.svg?style=shield)](https://circleci.com/gh/electron/electron/tree/master)
 [![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/4lggi9dpjc1qob7k/branch/master?svg=true)](https://ci.appveyor.com/project/electron-bot/electron-ljo26/branch/master)
 [![devDependency Status](https://david-dm.org/electron/electron/dev-status.svg)](https://david-dm.org/electron/electron?type=dev)
+[![Electron Discord Invite](https://img.shields.io/discord/745037351163527189?color=%237289DA&label=chat&logo=discord&logoColor=white)](https://discord.com/invite/electron)
 
 :memo: Available Translations: 🇨🇳 🇹🇼 🇧🇷 🇪🇸 🇰🇷 🇯🇵 🇷🇺 🇫🇷 🇹🇭 🇳🇱 🇹🇷 🇮🇩 🇺🇦 🇨🇿 🇮🇹 🇵🇱.
 View these docs in other languages at [electron/i18n](https://github.com/electron/i18n/tree/master/content/).