DEV: Document create group api params (#18736)

* DEV: Document create group api params

Documenting more params that are available to the create group api
endpoint.

* fix spelling

spec/requests/api/groups_spec.rb

@@ -11,7 +11,7 @@ RSpec.describe 'groups' do
   end
 
   path '/admin/groups.json' do
-    post 'Creates a group' do
+    post 'Create a group' do
       tags 'Groups'
       operationId 'createGroup'
       consumes 'application/json'

spec/requests/api/schemas/json/group_create_request.json

@@ -7,6 +7,82 @@
       "properties": {
         "name": {
           "type": "string"
+        },
+        "full_name": {
+          "type": "string"
+        },
+        "bio_raw": {
+          "type": "string",
+          "description": "About Group"
+        },
+        "usernames": {
+          "type": "string",
+          "description": "comma,separated"
+        },
+        "owner_usernames": {
+          "type": "string",
+          "description": "comma,separated"
+        },
+        "automatic_membership_email_domains": {
+          "type": "string",
+          "description": "pipe|separated"
+        },
+        "visibility_level": {
+          "type": "integer"
+        },
+        "primary_group": {
+          "type": "boolean"
+        },
+        "flair_icon": {
+          "type": "string"
+        },
+        "flair_upload_id": {
+          "type": "integer"
+        },
+        "flair_bg_color": {
+          "type": "string"
+        },
+        "public_admission": {
+          "type": "boolean"
+        },
+        "public_exit": {
+          "type": "boolean"
+        },
+        "public_exit": {
+          "type": "boolean"
+        },
+        "default_notification_level": {
+          "type": "integer"
+        },
+        "muted_category_ids": {
+          "type": "array",
+          "items": {
+            "type": "integer"
+          }
+        },
+        "regular_category_ids": {
+          "type": "array",
+          "items": {
+            "type": "integer"
+          }
+        },
+        "watching_category_ids": {
+          "type": "array",
+          "items": {
+            "type": "integer"
+          }
+        },
+        "tracking_category_ids": {
+          "type": "array",
+          "items": {
+            "type": "integer"
+          }
+        },
+        "watching_first_post_category_ids": {
+          "type": "array",
+          "items": {
+            "type": "integer"
+          }
         }
       },
       "required": [