Added instruction for playing music in voice chat with youtube link

readme.md

@@ -10,4 +10,9 @@ To install the bot do the following commands
 git clone https://gitlab.com/loicbersier/discordbot
 npm init -y
 npm install discord.js
+```
+If you want to play music with the bot you will need node-opus and ytdl-core
+```
+npm install node-opus
+npm install ytdl-core
 ```