Build a VOLTTRON BACnet registry CSV to map device points

Steps

1. Create one row per point with required columns: Volttron Point Name, Units, BACnet Object Type (e.g. analogInput, analogOutput, binaryValue, multiStateValue), Property (usually presentValue), Writable (TRUE/FALSE), and Index (the BACnet object instance number)
2. Mark Writable TRUE only for points that should be exposed to the Actuator Agent for writes — mislabeling a read-only point as writable causes write errors at runtime
3. Optionally add Write Priority (1-16, default 16 if blank) and a COV Flag column (TRUE establishes a BACnet Change-of-Value subscription for that point)
4. Add non-functional documentation columns (Point Name, Notes, Unit Details) freely — any column outside the required/optional set is ignored
5. Reference the CSV from the device config's registry_config field, either as a local path or a config-store reference