Update Mopidy doc #1165
Description
Needed, if MichaIng/DietPi#7955 is finished.
Doc to be changed: https://dietpi.com/docs/software/media/#mopidy
Check MichaIng/DietPi#7955 for changes, e.g.:
- change screenshot to new WebUI (Iris: https://mopidy.com/ext/iris/)
- add "update" tab
- add "view logs" tab
- add "service control" tab