website/docs: test build of new structure

[tanberry]

This PR has the new structure, minus the developer-docs. There are still 38 broken links but many of those are to the dev docs so will be fixed when I move them in.

NOTE: We won't merge this PR, I just wanted to push the latest version of the migratefile and sidebar.js so that they are in a safe space.

Next steps:

1. Create a new branch with latest from main
2. Verify that the latest files are in place: migratefile and sidebar.js
3. Install latest version of migration tool: cargo install --git https://github.com/ObamaTheLlama114/authentik --branch rework_docsmg
4. Navigate to /website
5. Run docsmg migrate
6. Manually move all of the Developer Docs into place
7. Write any stub index files that might be empty
8. Fix links
9. Build and test

• [ ] The documentation has been updated
• [ ] The documentation has been formatted (make website)