NodeJS 20 is almost EOL so I'm updating our workflows to use NodeJS 22.
This does not change anything about our app, which will still use NodeJS
20 until Electron shifts away from it. NodeJS 22 is fully
backwards-compatible with NodeJS 20 so there's no issue from a testing
standpoint.
## Summary
We are moving our docsite to this repo for better coordination.
## What's changed?
- The docsite codebase is now in docs/
- The docsite will replace storybook as the published GitHub Pages site
for this repo
- Storybook will now be hosted at https://docs.waveterm.dev/storybook
- A new CI workflow will validate any changes to Storybook or the
docsite
- A combined CD workflow will build and deploy Storybook and the docsite
as a single artifact
- The Build Helper workflow will now build an embedded version of the
docsite before building the app, ensuring the docsite version it has is
always the latest
