Add CI workflow to deploy a versioned MkDocs-based website to GitHub Pages

[umbynos]

On every push to the repository's default branch, deploy the repository's MkDocs-based static website to GitHub Pages.

Documentation content will sometimes apply only to a specific version of the project. For this reason, it's important
for the reader to be able to access the documentation for the specific version of the project they are using.

With the help of mike, the documentation system provides access to:

• The tip of the default branch ("dev")
• The latest release ("latest")
• Each minor version series (e.g., "1.2")

The website version is selectable via a menu on the website as well as the URL of each documentation page.

[per1234]

You missed adding the "base assets":
https://github.com/per1234/tooling-project-assets/blob/main/workflow-templates/deploy-mkdocs-versioned-poetry.md#1-install-workflow-and-assets UPDATE: I missed that the repository already had a website set up

I recommend adding the "Check Website" workflow as a companion to this one:
https://github.com/per1234/tooling-project-assets/blob/main/workflow-templates/check-mkdocs-task.md
That taskfile template also provides a website:serve task that is super useful for local testing during development on the website.

[per1234]

In order for the versioned website to work, it's necessary to add this to mkdocs.yml:

extra:
  version:
    provider: mike

Reference