Add Workflow for vydoc for V3 docs

[rossgalloway]

Need documentation for the V3 Vault contracts similar to the documentation for V2 Vault Contracts. We need a workflow to easily and effectively create documentation for the new contracts and a flow to add it to versioning.

Consider the potential changes being made to simplify versioning as seen in this pull request: #428. But the flow to create documentation from the smart contracts is mostly unrelated to how the site structure is set up.

Should be similar to this: https://github.com/yearn/yearn-devdocs?tab=readme-ov-file#generating-versioned-documentation, but with the new v3 repo.

[rossgalloway]

This is addressed in #474