Update README.md

Author: xyonico

README.md

@@ -1,2 +1,23 @@
 # PracticePlugin
-Plugin for Beat Saber to control playback speed
+Plugin for Beat Saber to control playback speed.
+
+[Video Preview](https://youtu.be/lzHlBAKJvyY)  
+![Preview](https://i.imgur.com/JE2ka4n.png)
+
+# Installation
+*This plugin requires IPA which you will automatically get if you install [the Song Loader Plugin](https://github.com/xyonico/BeatSaberSongInjector/releases).*
+
+1. Make sure that Beat Saber is not running.
+2. Extract the `PracticePlugin.dll` into the `Beat Saber/Plugins` folder.  
+	For Oculus Home: `.../Oculus Apps/Software/hyperbolic-magnetism-beat-saber`  
+	For Steam: `.../steamapps/common/Beat Saber`
+		(The folder that contains Beat Saber.exe)
+4. Done! You've installed the Practice Plugin.
+
+# Usage
+You will see the speed option in the pause menu if you play a song with **No Fail** enabled.
+
+---
+
+If you need help, ask us at the Beat Saber Mod Group Discord Server:
+https://discord.gg/Cz6PTM5