* sequencer: create togglable feature
* sequencer: add support for steps
* sequencer: add support for tempo and resolutions
* sequencer: schedule a message print at the right frequency
* sequencer: send a hardcoded note
* sequencer: add support for 8 tracks
* sequencer: play several notes simultaneously
* sequencer: only play the active tracks for a given step
* sequencer: change the default behavior of the track toggler
* sequencer: make number of tracks and track notes customizable
* sequencer: move the keycodes down
Not adding them at the end of the list apparently risks breaking
compatibility with VIA.
Source: https://github.com/qmk/qmk_firmware/pull/9703#discussion_r459202733
* sequencer: add unit tests
* sequencer: add unit test for matrix_scan_sequencer
* sequencer: expose internal state for better unit-testability
* sequencer: add unit tests for matrix_scan_sequencer
