docs(Readme): add AUR package mention, link badges

Author: Ruslan Garifullin

README.md

@@ -1,6 +1,7 @@
 # DiscordQt
-![DiscordQt CI](https://github.com/ruslang02/discord-qt/workflows/DiscordQt%20CI/badge.svg)
-![David](https://img.shields.io/david/ruslang02/discord-qt)
+[![AUR](https://img.shields.io/aur/version/discord-qt-appimage)](https://aur.archlinux.org/packages/discord-qt-appimage)
+[![DiscordQt CI](https://github.com/ruslang02/discord-qt/workflows/DiscordQt%20CI/badge.svg)](https://github.com/ruslang02/discord-qt/actions)
+[![David](https://img.shields.io/david/ruslang02/discord-qt)](https://github.com/ruslang02/discord-qt/blob/master/package.json)
 
 [![discord](https://img.shields.io/discord/765296053410857000?color=%237289da&label=discord&logo=discord&logoColor=white&style=for-the-badge)](https://discord.gg/tNNuUK4)
 
@@ -13,6 +14,10 @@ It offers a significantly less resource-consuming experience comparing to the of
 
 ![Screenshot](screenshot.png)
 
+## Arch Linux and derivatives
+
+This application is also available in Arch User Repository (AUR): [discord-qt-appimage](https://aur.archlinux.org/packages/discord-qt-appimage/)
+
 ## Building from sources
 
 [Node.JS v10+](https://github.com/nodejs/node) is required to build.