[TASK] Automated generation of repo's docs into GitHub Pages



https://github.com/github/spec-kit/tree/main/docs

So the documentation will be automatically built and deployed to **GitHub Pages** when changes are pushed to the main branch. 
The workflow can be similar to this workflow in .github/workflows/docs.yml:

https://github.com/github/spec-kit/blob/main/.github/workflows/docs.yml 