[Feature Request /Proposal] Moving the Handbook to a new framework.

This issue is on the back of a discussion that has been had on the discord, and is to ensure proper etiquette before attempting a PR with such a radical change.

The proposal is to move the Developers Handbook to a new framework (most likely Material for MkDocs, the framework used for the [blender documentation](https://docs.blender.org/).

The goal of the initiative would be to have a framework that still is easy to contribute to, whilst also having the QoL features that would improve the on-boarding of developers whom are thinking of becoming contributors.

Start by reviewing the Discord discussion referenced in the issue and the current Developers Handbook structure. Compare the existing handbook with Material for MkDocs and the Blender documentation example, then establish the agreed framework and migration scope; completion would require consensus before a migration PR is attempted.

Written by the indexing model from the issue text.