Unify doc-strings (remove type/rtype)

As this information is already provided in type hints and we don't need to maintain it in two places.

src/ifcopenshell-python/ifcopenshell/api/document/add_information.py

@@ -37,9 +37,7 @@ def add_information(
     is considered the latest version and the children are older revisions.
 
     :param parent: The parent document, if necessary.
-    :type parent: ifcopenshell.entity_instance, optional
     :return: The newly created IfcDocumentInformation entity
-    :rtype: ifcopenshell.entity_instance
 
     Example:
 

src/ifcopenshell-python/ifcopenshell/api/document/remove_information.py

@@ -28,9 +28,7 @@ def remove_information(file: ifcopenshell.file, information: ifcopenshell.entity
     All references and associations are also removed.
 
     :param information: The IfcDocumentInformation to remove
-    :type information: ifcopenshell.entity_instance
     :return: None
-    :rtype: None
 
     Example:
 

src/ifcopenshell-python/ifcopenshell/api/document/remove_reference.py

@@ -26,9 +26,7 @@ def remove_reference(file: ifcopenshell.file, reference: ifcopenshell.entity_ins
     All associations with objects are removed.
 
     :param reference: The IfcDocumentReference to remove
-    :type reference: ifcopenshell.entity_instance
     :return: None
-    :rtype: None
 
     Example: