Tc mux docs

[Comerm28]

No description provided.

[jhwang04]

Good work overall, just take extra care to proofread and edit for clarity. If a spelling mistake slips through occasionally, that's totally fine, but I shouldn't be catching multiple of them per commit. Documentation is important, and we should be writing it clearly and professionally.

And yes, I know I'm being fairly nitpick-y. These restrictions will relax as time goes on, but it's worth taking the extra time to write bulletproof documentation before we move towards HT09 firmware. We've had lengthy ongoing discussions about the obscurity and unreadability of firmware in general, and we need to focus hard on paying off our tech debt while we can. I'm not going to be satisfied with any amount of "we'll fix it later"s at this point in time.