Add:
- Option to turn off Seek button
- Option to turn off Platform indicator
- Option to disable duration placeholder
- Adjustable thumbnail roundness
- Song's details button
- New Discord Rich Presence library

Fixes:
- App crashes randomly with Conversion exception
- Playback speed button spacing issue
- Minor setting entries with slider's indentation

Changes:
- More meaningful messages instead of "Required value is null"
- Improve fadein/fadeout effect when play/pause from an external source