Added gender

docs/API_REFERENCE.md

@@ -208,6 +208,7 @@ Role requirements are called out per endpoint below. If the signed-in member lac
   "name": "Kiwi",
   "tagId": "FP-001",
   "species": "Cockatiel",
+  "gender": "female",
   "dateOfBirth": "2023-05-10",
   "gotchaDay": "2023-08-21",
   "chartColor": "#cb3a35",
@@ -250,6 +251,7 @@ Role requirements are called out per endpoint below. If the signed-in member lac
 - Dates use `YYYY-MM-DD`
 - `workspaceType` is `standard` or `rescue`
 - member `role` is `owner`, `manager`, `staff`, or `viewer`
+- bird `gender` is `unknown`, `male`, or `female`
 - bird `chartColor` must be a `#RRGGBB` hex color
 - `photoDataUrl` must be a base64 `data:image/...` URL
 - `weightGrams` must be a positive number up to `10000`
@@ -701,6 +703,7 @@ Request body:
   "name": "Kiwi",
   "tagId": "FP-001",
   "species": "Cockatiel",
+  "gender": "female",
   "dateOfBirth": "2023-05-10",
   "gotchaDay": "2023-08-21",
   "chartColor": "#cb3a35",