[main] Automate build docs and publish to gh pages process

[kaytcat]

No description provided.

[feychou]

I would also suggest that we switch the publishing branch from master to gh-pages.

This is because I would love to:

• remove the dist folder from master and keep it its own branch;
• leave the gh-pages branch to complete automatic maintenance: once we publish a new version, we also publish the docs along with it with hooked script. This would also keep the docs consistent to the current version of nukleus, which I think is the expected behaviour.