Link to the glossary for "magic methods" in MagicMock (#111292)

The MagicMock documentation mentions magic methods several times without
actually pointing to the term in the glossary. This can be helpful for
people to fully understand what those magic methods are.

Doc/library/unittest.mock.rst

@@ -2009,8 +2009,8 @@ Mocking Magic Methods
 ~~~~~~~~~~~~~~~~~~~~~
 
 :class:`Mock` supports mocking the Python protocol methods, also known as
-"magic methods". This allows mock objects to replace containers or other
-objects that implement Python protocols.
+:term:`"magic methods" <magic method>`. This allows mock objects to replace
+containers or other objects that implement Python protocols.
 
 Because magic methods are looked up differently from normal methods [#]_, this
 support has been specially implemented. This means that only specific magic
@@ -2108,8 +2108,8 @@ There are two ``MagicMock`` variants: :class:`MagicMock` and :class:`NonCallable
 .. class:: MagicMock(*args, **kw)
 
    ``MagicMock`` is a subclass of :class:`Mock` with default implementations
-   of most of the magic methods. You can use ``MagicMock`` without having to
-   configure the magic methods yourself.
+   of most of the :term:`magic methods <magic method>`. You can use
+   ``MagicMock`` without having to configure the magic methods yourself.
 
    The constructor parameters have the same meaning as for :class:`Mock`.