Add API documentation for group module

src/ifcopenshell-python/ifcopenshell/api/group/edit_group.py

@@ -18,12 +18,28 @@
 
 
 class Usecase:
-    def __init__(self, file, **settings):
+    def __init__(self, file, group=None, attributes=None):
+        """Edits the attributes of an IfcGroup
+
+        For more information about the attributes and data types of an
+        IfcGroup, consult the IFC documentation.
+
+        :param group: The IfcGroup entity you want to edit
+        :type group: ifcopenshell.entity_instance.entity_instance
+        :param attributes: a dictionary of attribute names and values.
+        :type attributes: dict, optional
+        :return: None
+        :rtype: None
+
+        Example::
+
+            group = ifcopenshell.api.run("group.add_group", model, Name="Unit 1A")
+            ifcopenshell.api.run("group.edit_group", model,
+                group=group, attributes={"Description": "All furniture and joinery included in the unit"})
+        """
+
         self.file = file
-        self.settings = {
-            "group": None, "attributes": {}}
-        for key, value in settings.items():
-            self.settings[key] = value
+        self.settings = {"group": group, "attributes": attributes or {}}
 
     def execute(self):
         for name, value in self.settings["attributes"].items():