* feat: make double tap to hold layer optional per key
* test: fix test serializer
* fix: remove "application start" text
* Add double-tap.svg
* Add closing dot at the end of the sentence.
* fead: add double-tap icon
* Bundle firmware version 8.3.0
* feat: 'layer-double-tap' feature flag
* feat: convert SwitchLayerMode to string enum