Document any TYPE_CHECKING name works (#18443)

Document any TYPE_CHECKING name works (#18443) · python/mypy@c4e2eb7

Original file line number	Diff line number	Diff line change
`@@ -455,7 +455,7 @@ Example:`
`455`	`455`	`# The rest of this file doesn't apply to Windows.`
`456`	`456`
`457`	`457`	`Some other expressions exhibit similar behavior; in particular,`
`458`		-:py:data:`~typing.TYPE_CHECKING`, variables named ``MYPY``, and any variable
	`458`	+:py:data:`~typing.TYPE_CHECKING`, variables named ``MYPY`` or ``TYPE_CHECKING``, and any variable
`459`	`459`	whose name is passed to :option:`--always-true <mypy --always-true>` or :option:`--always-false <mypy --always-false>`.
`460`	`460`	(However, ``True`` and ``False`` are not treated specially!)
`461`	`461`