* Remove chording as it is not documented, not used, and needs work.
* Make Leader Key an optional feature.
* Switch from `PREVENT_STUCK_MODIFIERS` to `STRICT_LAYER_RELEASE`
* Remove `#define PREVENT_STUCK_MODIFIERS` from keymaps.
* Fix serial split for BFO9000
* Fix serial split for DeltaSplit75
* Fix serial split for Helix
* Fix serial split for MiniDox
* Fix serial split for Viterbi
* Revert "Fix serial split for Helix" since it's super complex
This reverts commit 72538df105.
We'll let the helix owner fix this issue, or dive into the code later
Drashna Jaelre