add class-customization to pydoc topics

Author: adqm

Doc/tools/extensions/pydoc_topics.py

@@ -41,6 +41,7 @@
     "callable-types",
     "calls",
     "class",
+    "class-customization",
     "comparisons",
     "compound",
     "context-managers",

Lib/pydoc.py

@@ -1865,7 +1865,7 @@ def collect_dunders(symbols):
         '__format__', '__hash__', '__bool__',
     ]
     for bd in basic_dunders:
-        dunders[bd] = ('customization', 'SPECIALMETHODS')
+        dunders[bd] = ('class-customization', 'SPECIALMETHODS')
 
     attribute_dunders = [
         '__getattr__', '__getattribute__', '__setattr__', '__delattr__',