Integrate new docs site with changesets

[lightwalker-eth]

Goals

1. Enable us to create changesets in relation to the new Mintlify docs site.
2. See changesets related to the new Mintlify docs site in our release notes.
3. Keep the version number of the new Mintlify docs site pinned / fixed with the version number of all our other apps in the ENSNode monorepo.

Subtasks

• Update: https://github.com/namehash/ensnode/blob/main/.changeset/config.json#L7-L27
• I imagine we would need to create a "dummy" package.json file here for the purposes of changesets? https://github.com/namehash/ensnode/tree/main/docs/docs.ensnode.io Advice appreciated.
• Create a changeset announcing the creation of the new Mintlify docs site.
• Create a changeset announcing the creation of the new OpenAPI docs.