Make face tagging easier and more clearer

[ghost]

Is your feature request related to a problem? Please describe.
I find it very challenging fimnding out how to taga faces in the pictures

Describe the solution you'd like
Can someoje document a step by step process or modify the UI to possibly include a menu button to trigger the routinr

Describe alternatives you've considered (optional)
A User Menu item to trigger face tgging maybe more riendkyfor touchsreen qrfdckjces

[rhatguy]

PiGallery2 does not CREATE face tags today. You would create the tags with an external program such as DigiKam or Mylio that writes the tags either into the pictures files or in an XMP sidecar. PiGallery2 would then pick up those tags from the files and display them.

[bpatrik]

+1 to what @rhatguy said. See #292 about how I use the app myself.

mainly this line: "* tag faces. Ligthroom mediumly helpful with this. At some point I would like to implement face detection for pigallery2 #57. Until that is ready, I do it manually, so by the time it is ready, the ML model would already have some samples to classify the faces too."