Confirm the expected layout of enforceBranches config

[jonhall54]

Backend is erroring when attempting to use enforceBranches specifically:
{"severity":"WARNING","org":"org","repo":".allstar","file":"branch_protection.yaml","error":"json: cannot unmarshal array into Go struct field OrgConfig.enforceBranches of type map[string][]string","time":"2024-12-18T15:57:20Z","message":"Malformed config file, using defaults."}

Reviewing the documentation and trying different layouts the error persists. Any confirmation of the layout would be very helpful.