docs(omitTrack): described toggles

README.md

@@ -28,3 +28,19 @@ Compress videos with FFmpeg made easy with drag'n'drop.
 ## Usage
 After running the installation script, you can simply drag'n'drop (drag and drop) the video file(s) onto `dragAndDropVideoFileHere.ps1`.  
 You can also create one or more shortcuts to `dragAndDropVideoFileHere.ps1` anywhere and drag'n'drop the video file(s) onto the shortcut(s).
+
+### Advanced usage
+It is possible for video files to contain multiple audio tracks.
+This is often used in screen recording to separate individual sound sources, for example microphone and game.
+
+The script in v1.0.0 merges all audio track into one.
+
+It is possible to spare the first and/or the last track.
+
+To do that, go into the file `dragAndDropVideoFileHere.ps1` and alter the values in the lines 25 and or 26:
+```
+[bool] $omitFirstAudioTrack = 0
+[bool] $omitLastAudioTrack = 1
+```
+`0` means deactivate
+`1` means activate