add screenshots off app to readme

[DeanLemans]

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3. Please provide all relevant information below.

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• Vanilla Music Version (Settings -> About):
• Android Version:
• Phone vendor / model:
• Application was downloaded from (use [x]):
  • [ ] Play Store
  • [x] F-Droid
  • [ ] Other (Nightly Build)
• Did this work in a previous version?
  • [ ] Yes
  • [ ] No
  • [x ] NA / Don't know.

Description

Put screenshots of the app in the readme

Steps to reproduce the issue

NaN

Screenshot / Video (If applicable)

Nah