Reorganize docs sections and split cheatsheet in two

[Dewb]

What does this PR do?

Reorganizes op documentation. Splits some categories that have grown large, adds short descriptions to some ops that did not have any. Moves some ops between sections for better learnability. Reorders the sections so they fit on the cheatsheets better with fewer sections split across page breaks.

Splits the cheatsheet into separate "core" and "i2c" PDFs. The core PDF is 4 pages, the i2c PDF is 7 pages.

Example output:

• teletype.pdf
• cheatsheet.pdf
• cheatsheet-i2c.pdf

Major category changes:

• Pitch, Rhythm, and Randomness sections broken out of Maths
• Some Variables ops move into Randomness
• Seed merged into Randomness
• Some Hardware ops move into Calibration
• Perhaps most controversially, V and VV move from Maths to Hardware

Provide links to any related discussion on lines.

This came out of conversations in the teletype study group Discord.

How should this be manually tested?

See example docs output above.

Any background context you want to provide?

n/a

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

I have,

• updated CHANGELOG.md and whats_new.md
• updated the documentation
• (n/a) updated help_mode.c (if applicable)

[tehn]

looks great! @dndrks can you get these uploaded to the main docs page also?

[dndrks]

@Dewb !! amazing amazing amazing!!!
thank you so much.
merged into main docs: https://monome.org/docs/teletype/#learning-teletype