dev/ci: render per-RunType and per-diff pipeline docs
Created by: bobheadxi
Add a -docs
flag to the pipeline generator to demonstrate reference generation leveraging refactors introduced by the PRs this PR is stacked upon. This is a starting point for what I hope to be a helpful, always-up-to-date generated reference that we can include in https://docs.sourcegraph.com for #30203 (closed)
Also adds sg ci docs
with nice Markdown output with glamour:
sg ci docs