update changelog with 3.6.1 changes

Author: topi314

CHANGELOG.md

@@ -3,6 +3,9 @@
 Each release usually includes various fixes and improvements.
 The most noteworthy of these, as well as any features and breaking changes, are listed here.
 
+## 3.6.1
+* update lavaplayer to `1.3.99`. For me info see [here](https://github.com/freyacodes/Lavalink/pull/768)
+
 ## 3.6.0
 * new userId & clientName getters in the plugin-api. For more info see [here](https://github.com/freyacodes/Lavalink/pull/743).