docx: Full re-write of the Concourse site using MkDocs

[kcbimonte]

BLUF

As a Concourse Contributor, I want to modernize the Concourse docs using MkDocs, so that I can lower the barrier of entry for contributing new information.

Task List

Current task list:

• Move all existing files to .old
• Create skeletons for all pages
• Create redirects for all pages
• Transfer all docs information over
• Transfer all blog information over
• Determine how to display schemas
• Determine how to create homepage
• Update CI to support mkdocs (could use mkdocs gh-deploy --force) for ease of use

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: analytically / name: Mathias Bogaert (d0be8d9)
• ✅ login: kcbimonte / name: Kevin C. Bimonte (16af877, 1bb7617, 30bb827, 3ae2c8b, 410e497, 4761273, 48f82b0, 5126714, 5970766, 5f81952, 61013ac, 6842e2d, 6f92119, 8826c22, 88bfe46, 9073457, 9bc6731, ab9abed, b0a9b0a, b6bd2c8, c353474, d0870dd, d3ff613, d69a9cc, e5aa45f, e81cb19, f51b46f)
• ✅ login: taylorsilva / name: Taylor Silva (0a25b53, 120c7d7, 6763521, 6c85bb9, a03a452, b86d9cb, bb6929f, c1edacb)

[taylorsilva]

This just came across my feed: https://squidfunk.github.io/mkdocs-material/blog/2025/11/05/zensical/

Some interesting tidbits:

• Mkdocs is unmaintained (?). Last release is August 2024 and master branch has received very few commits. I did not notice this before.
• Material for MkDocs is now in maintenance mode and the team behind it started zensical as a successor to mkdocs

I don't think we should try switching to their thing now. I think making this jump, booklit to Mkdocs, is a good first step. Then we can possibly look at moving over to Zensical. They mention they're putting significant effort into the mkdocs -> zensical migration path.

[kcbimonte]

Yup, just saw that as well and was going to suggest a slight pause on this to see how this whole Zensical thing played out before going any further.

[kcbimonte]

Determined how to do CI I believe. This will also clear out a bunch of junk from the gh-pages branch that shouldn't be there but is navigable:

• New build script: https://github.com/Aviator-Labs/docs-ci/blob/docs-rewrite/ci/build
• Example of routable less files: https://concourse-ci.org/less/base.less