update readme

README.md

@@ -191,6 +191,17 @@ Body
 }
 ```
 
+Create a new permission for a group
+
+Body
+```
+{
+    "Description": "Group access to default safe",
+    "safeId": 1,
+    "groupId": 1
+}
+```
+
 Creates a new permission mapping user/group to safe. Currently the create permission operation requires knowing the correct user Id or group Id, as well as the safe Id onto which permissions will be granted. This operation can only be performed by a user that is admin enabled. 
 
 #### Delete Permission