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/library/add_library.py

@@ -50,9 +50,7 @@ def add_library(file: ifcopenshell.file, name: str) -> ifcopenshell.entity_insta
     to a particular table and row within that database.
 
     :param name: The name of the library
-    :type name: str
     :return: The newly created IfcLibraryInformation
-    :rtype: ifcopenshell.entity_instance
 
     Example:
 

src/ifcopenshell-python/ifcopenshell/api/library/add_reference.py

@@ -35,9 +35,7 @@ def add_reference(file: ifcopenshell.file, library: ifcopenshell.entity_instance
     library's references.
 
     :param library: The IfcLibraryInformation element to add a reference to
-    :type library: ifcopenshell.entity_instance
     :return: The newly created IfcLibraryReference element
-    :rtype: ifcopenshell.entity_instance
 
     Example:
 

src/ifcopenshell-python/ifcopenshell/api/library/remove_library.py

@@ -27,9 +27,7 @@ def remove_library(file: ifcopenshell.file, library: ifcopenshell.entity_instanc
     products which have relationships to this library will not be removed.
 
     :param library: The IfcLibraryInformation entity you want to remove
-    :type library: ifcopenshell.entity_instance
     :return: None
-    :rtype: None
 
     Example:
 

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

@@ -27,9 +27,7 @@ def remove_reference(file: ifcopenshell.file, reference: ifcopenshell.entity_ins
     removed.
 
     :param reference: The IfcLibraryReference entity you want to remove
-    :type reference: ifcopenshell.entity_instance
     :return: None
-    :rtype: None
 
     Example: