feat(ci): Add Docs build at CI

[vic]

This is to prevent accepting PR that break the site build.

Fixes #269

[ulfbayte]

@vic Sorry for this...
Can I use some tool to avoid this situation next time ? (edit ok it's pnpm stuff, I will try to build before submitting instead of relying on preview)

[vic]

Can I use some tool to avoid this situation next time ? (edit ok it's pnpm stuff, I will try to build before submitting instead of relying on preview)

no worries, I understand, I actually want people to submit PR directly from their browser, that's why we have that "Edit this page" button. If you however have a clone of the repo you can run pnpm run build or pnpm run dev to see your changes locally. I added a github action just to prevent errors reaching main branch, I still want people to send PRs and I'm willing to fix them if they dont have the project, #270 is a way to alert me (or contributors) before merging.