Add MkDocs site for the documentation

[Karneades]

Hi Kelsey

Thanks a lot for your project and documentation around Kubernetes.

As I came across your repo, I just wondered, what do you think about a MkDocs variant of your documentation repo? Would you be interested in making the docs available as a GitHub page?

For a quick test I just added the introduction from the readme to the docs and the MkDocs config file (see commit). It has some Previous and Next buttons in the footer, a simple side navigation and a powerful search from MkDocs. If we go with such a static site generator, we can remove the manual "Next" links at the end of each file.

• Demo https://karneades.github.io/kubernetes-the-hard-way/
• Fork: https://github.com/Karneades/kubernetes-the-hard-way

[Karneades]

Changes to fork since initial post:

• add link to GitHub
• add buttons to jump quickly to GitHub for editing the page at hand
• add workflow for building and deploying the site to the gh_pages branch directly after merge to master/main which is then pushed to the GitHub pages site.