Add screenshots on F-Droid

[Korb]

There are currently no screenshots on this app's page in the F-Droid catalog. Without a preview, only by a text description, it is difficult to decide whether to download and install the application or not. I propose to add a few screenshots that most fully describe the appearance and functionality of the application.

All About Descriptions, Graphics, and Screenshots

Fastlane file structure / Quick Fastlane Cheat-Sheet