Add generateCommandTable() to help.ts and a generation script that
produces two artifacts: a Markdoc partial for the command table and
a full CLI reference page. Both are generated by script/generate.ts
and auto-committed by the generate.yml workflow on push to dev.
Replace hand-written command table in cli.md with the generated
partial and add a nav entry for the new CLI Command Reference page.
Closes#572
maphew