PEP 560: Add Typing label (#3753)

I was looking for this PEP on 
https://peps.python.org/topic/typing/ but because
it's missing the label, the sphinx pep_zero_generator
skipped this one.

Author: Hnasar

peps/pep-0560.rst

@@ -3,6 +3,7 @@ Title: Core support for typing module and generic types
 Author: Ivan Levkivskyi <[email protected]>
 Status: Final
 Type: Standards Track
+Topic: Typing
 Created: 03-Sep-2017
 Python-Version: 3.7
 Post-History: 09-Sep-2017, 14-Nov-2017