Update documentation for Home Assistant light management and room configuration

- Added a new section in README.md for creating and managing lights by room in Home Assistant, linking to a focused guide.
- Enhanced the all-lights-and-rooms.md documentation with a reference to the new guide for clarity on entity creation and room assignment.
- Made minor adjustments to the room-config.js file, commenting out outdated device-to-room mappings to improve code clarity.

This update improves the documentation and usability for users managing lights and rooms in Home Assistant.

docs/integration/all-lights-and-rooms.md

@@ -160,6 +160,8 @@ Generate this list from your room list + lights per room (e.g. 16 rooms × up to
 
 ## 4. Home Assistant: creating entities for all lights
 
+For a focused guide on **creating entities and assigning them to rooms (Areas)** in HA, see **[ha-lights-and-rooms.md](ha-lights-and-rooms.md)**.
+
 You need one HA entity per light (or per zone) that Node-RED and the PLC treat as one target. Two common choices:
 
 - **`input_boolean`** – simple on/off, good for “virtual” switches that only drive the PLC.