Add documentation for pset API module

src/ifcopenshell-python/ifcopenshell/api/pset/remove_pset.py

@@ -18,11 +18,29 @@
 
 
 class Usecase:
-    def __init__(self, file, **settings):
+    def __init__(self, file, product=None, pset=None):
+        """Removes a property set from a product
+
+        All properties that are part of this property set are also removed.
+
+        :param product: The IfcObject to remove the property set from.
+        :type product: ifcopenshell.entity_instance.entity_instance
+        :param pset: The IfcPropertySet or IfcElementQuantity to remove.
+        :type pset: ifcopenshell.entity_instance.entity_instance
+        :return: None
+        :rtype: None
+
+        Example::
+
+            # Let's imagine we have a new wall type with a property set.
+            wall_type = ifcopenshell.api.run("root.create_entity", model, ifc_class="IfcWallType")
+            pset = ifcopenshell.api.run("pset.add_pset", model, product=wall_type, name="Pset_WallCommon")
+
+            # Remove it!
+            ifcopenshell.api.run("pset.remove_pset", model, product=wall_type, pset=pset)
+        """
         self.file = file
-        self.settings = {"product": None, "pset": None}
-        for key, value in settings.items():
-            self.settings[key] = value
+        self.settings = {"product": product, "pset": pset}
 
     def execute(self):
         to_purge = []