bpo-35054: Add yet more index entries for symbols. (GH-10121)

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index efbc872..6067c72 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1835,7 +1835,7 @@
 .. index::
    single: metaclass
    builtin: type
-   single: =; class definition
+   single: = (equals); class definition
 
 By default, classes are constructed using :func:`type`. The class body is
 executed in a new namespace and the class name is bound locally to the