Pattern mode key bindings

[discohead]

What does this PR do?

Adds the following keybindings to pattern/tracker mode:

ALT-[ ]|SEMITONE UP, DOWN
CTRL-[ ]|FIFTH UP, DOWN
SH-[ ]|OCTAVE UP, DOWN
ALT-<0-9>|NUM SEMITONES UP
// 0 = 10 and 1 = 11
SH-ALT-<0-9>|NUM SEMITONES DOWN
// 0 = 10 and 1 = 11

Demo video: https://www.youtube.com/watch?v=gxOZY_MgsvE

Provide links to any related discussion on lines.

https://llllllll.co/t/teletype-firmware-discussion/13961/41

How should this be manually tested?

1. Enter Pattern/Tracker Mode
2. Try key commands listed above
3. Verify values entered match values in N table

Any background context you want to provide?

If the related Github issues aren't referenced in your commits, please link to them here.

I have,

• updated CHANGELOG.md
• updated the documentation
• run make format on each commit

NOTE: make format formatted a bunch of lines in help_mode.c that were not in my original changeset

[tehn]

@scanner-darkly @csboling

whoa. there hasn't been an official TT version bump since last july. time for 3.2.0?

[discohead]

@tehn I've made a couple of cool new ops as well. I'll make a PR for those tonight so you can take a look to see if you want to include them.

[scanner-darkly]

will take a look at all the PRs tonight!