Write documentation for sequence API module

src/ifcopenshell-python/ifcopenshell/api/sequence/assign_workplan.py

@@ -21,11 +21,33 @@ import ifcopenshell.api
 
 
 class Usecase:
-    def __init__(self, file, **settings):
+    def __init__(self, file, work_schedule=None, work_plan=None):
+        """Assigns a work schedule to a work plan
+
+        Typically, work schedules would be assigned to a work plan at creation.
+        However you may also delay this and do it manually afterwards.
+
+        :param work_schedule: The IfcWorkSchedule that will be assigned to the
+            work plan.
+        :type work_schedule: ifcopenshell.entity_instance.entity_instance
+        :param work_plan: The IfcWorkPlan for the schedule to be assigned to.
+        :type work_plan: ifcopenshell.entity_instance.entity_instance
+        :return: The IfcRelAggregates relationship
+        :rtype: ifcopenshell.entity_instance.entity_instance
+
+        Example::
+
+            # This will hold all our construction schedules
+            work_plan = ifcopenshell.api.run("sequence.add_work_plan", model, name="Construction")
+
+            # Alternatively, if you create a schedule without a work plan ...
+            schedule = ifcopenshell.api.run("sequence.add_work_schedule", model, name="Construction Schedule A")
+
+            # ... you can assign the work plan afterwards.
+            ifcopenshell.api.run("sequence.assign_workplan", work_schedule=schedule, work_plan=work_plan)
+        """
         self.file = file
-        self.settings = {"work_schedule": None, "work_plan": None}
-        for key, value in settings.items():
-            self.settings[key] = value
+        self.settings = {"work_schedule": work_schedule, "work_plan": work_plan}
 
     def execute(self):
         # TODO: this is an ambiguity by buildingSMART