Update documentation with hwaccleration issues

install/config.example.yml

@@ -28,6 +28,7 @@ database:
 transcode:
   #may result in higher latency if your cpu can't keep up
   adaptive: false
+  #more than 3 might cause problems when using hwacceleration
   variants: 3
   #unused right now, will always transcode to dash
   format: dash