docs: add a Room of Requirement unlocks guide

[Kheartz]

Adds a Room of Requirement guide on opening the parts of a room and giving players the conjuration recipes, and corrects two lines in Rooms that no longer match 1.9.

New: Wings, vivariums and recipes (guides/Room of Requirement/unlocks.md)

• The thirteen room locks (expansions, vivarium biomes, initial dressing, the lighting choice) and what each opens, with a sample that loads a fully open room.
• Opening or closing a part of a loaded room by loading it again with the changed lock, and the in-place reload that follows.
• Conjuration recipes as per-player game locks: opened on the client with Doors.setLock, not saved, so re-sent on every join. The sample has the server decide and the client hold the list.
• The full list of 307 recipe lock ids, taken from the game data.

Rooms (guides/Room of Requirement/rooms.md)

• Editors no longer open parts of a room: since mod 664b4d0f the room's locks are the server's.
• An editor's lighting change now reaches everyone else in the room at once (mod d880a541), not on their next entry.
• The locks row and "Where to go next" link to the new guide.

Also lists the guide in the overview. node scripts/check_samples.mjs passes locally: 169 samples in 47 guides against the 1.9.0 contract.