Add Keyboard Shortcuts to Music Editor

[ARival]

The music editor (tracker) would benefit from some additional keyboard shortcuts. They could be static or assignable via menu or configuration file.

I've attached Famitracker's default keyboard shortcuts as a starting point.

Del | Delete selection / selected row
Backspace | Delete the row above
Insert | Insert rows below
Ctrl+F1 | Decrease notes by Semitone
Ctrl+F2 | Increase notes by Semitone
Ctrl+F3 | Decrease octaves
Ctrl+F4 | Increase octaves
Space | Switch between edit / normal mode
Ctrl+Right | Jump forward one frame
Ctrl+Left | Jump backward one frame
Tab | Go to to next channel
Shift+Tab | Go to to previous channel
+ | Next pattern
- | Previous pattern
Numpad 0-9 | Select instrument 0 - 9
Ctrl+Numpad 0-9 | Set step size, 0 - 9
/ | Select previous octave
* | Select next octave
Ctrl+Up | Next instrument
Ctrl+Down | Previous instrument
Ctrl+I | Interpolate selected values

[nesbox]

Thank you 👍

[nesbox]

Added new music editor shortcuts 14210c4:

Del | Delete selection / selected row
Backspace | Delete the row above
Insert | Insert rows below
Ctrl+F1 | Decrease notes by Semitone
Ctrl+F2 | Increase notes by Semitone
Ctrl+F3 | Decrease octaves
Ctrl+F4 | Increase octaves
Space | Play current track
Ctrl+Right | Jump forward one frame
Ctrl+Left | Jump backward one frame
Tab | Go to next channel
Shift+Tab | Go to previous channel
+ | Next pattern
- | Previous pattern
Ctrl+Up | Next instrument
Ctrl+Down | Previous instrument

except these, seems they don't fit the Music Editor

Numpad 0-9 | Select instrument 0 - 9
Ctrl+Numpad 0-9 | Set step size, 0 - 9
/ | Select previous octave
* | Select next octave
Ctrl+I | Interpolate selected values

Please, check the latest build https://github.com/nesbox/TIC-80/actions/runs/749044345
Thank you.