Documentation is not updated since 2021

[sh-cho]

Hello, I'm trying to use promgen and looked around documentation a bit, and noticed something is off.

What's wrong?

• Current gh-pages release: https://line.github.io/promgen/

Looks like current documentation is published in Mar 30, 2021 and it is not updated since then.

And in sphinx.yml, it checks github reference if it is same with refs/heads/main, which should be actually refs/heads/master.

So Deploy to GitHub Pages step is always skipped, so that documentation is not published.

How to fix

Checking if github ref is master is an easy fix, but it's not enough.

gh-pages branch is not necessary, because in github, it is possible to directly deploy 'pages' with github actions (⚠️ if only changed repository settings)

In this case, generated files are attached as "Artifacts" in actions, and it is possible to deploy Artifacts with actions/deploy-pages, so no need to use third-party action (e.g. JamesIves/github-pages-deploy-action)

I will make PR shortly, but if you have another opinion, please let me know!