Move Docsy repos into their own GH organisation

[chalin]

As discussed during the PSC meeting of 2024-05-07. Moving repos into their own org will better support:

• Creating a community-managed repo for community contributions (as a step towards the "plugin" architecture discussed in Docsy's long-term vision)
• Addressing the project's access-permission needs, which includes, but is not limited to:
  • Inviting external collaborators into the org
  • Creating & managing org-level groups; see,
    #1735