Deprecate Docs Directory

[emnul]

• Remove docs tasks from turbo.json
• Remove docs filters from package.json scripts
• Create a docs branch then update the playbook on the old docs repo here like this:

    - url: https://github.com/OpenZeppelin/compact-contracts
      branches:
        - docs-v*
      start_path: docs

so it can fetch the last prerelease (as opposed to reading from HEAD as it is now)

• Create subtree that points to OpenZeppelin/docs