Revamp wsample->wgt; Add keydowns

The new wgt (formerly wsample) shows one way to sort-of-simply do in-file hash tables with the new adix/oats.

keydowns is one sort of semi-objective attempt at being more precise about keyboard-entry ergonomics. It's been referenced / used in doc/rp.nim quite a bit already.

Also update doc/tim.md quite a bit and bump cligen dependency to not have fmtUncertain* bugs.