Foreman documentation site improvements

Hello all,

I have improved documentation deployment workflow which is hosted on Github (Actions + Pages). All content from master branch is built into /nightly prefix. I have implemented a small 404 page that automatically recognizes URLs with /master and offers the new destination.

Next, I have implemented branching and pushed the very first version 2.3 which is now available through the main menu. The landing site definitely needs more love, currently it only provides links to the guides, we can probably present Headline Features and Changelog on that page in the future.

Another huge change is that the static site (menu, langing pages, 404 page) is now generated via Hugo static site generator. If you want to help improving this site, just install the hugo command which is in most Linux distributions and run web# hugo server to generate the site.

During my work, I encountered way to many HTML validation failures, so I made this Github Action non-fatal. It should not fail the pipeline, however I don’t know if Github will show red color - I need to find out. Pay attention when merging PRs for some time.

One last thing, we currently build also PDF books and they can be downloaded from the Github Action as artifacts. With every major release, we could publish those PDFs on our downloads site, commiting them into gh-pages is a definitely no-go (they are huge). Can someone help me to find the right place and way to upload those PDFs? Manually would be probably fine for now, however if someone can automate that that would be awesome.

The branching process is documented in the README, so we are ready for the 2.4 release. The infrastructure is ready, I am looking forward what’s next with our documentation.