bpo-38738: Fix formatting of True and False. (GH-17083)
* "Return true/false" is replaced with "Return ``True``/``False``"
if the function actually returns a bool.
* Fixed formatting of some True and False literals (now in monospace).
* Replaced "True/False" with "true/false" if it can be not only bool.
* Replaced some 1/0 with True/False if it corresponds the code.
* "Returns <bool>" is replaced with "Return <bool>".
diff --git a/Doc/library/email.message.rst b/Doc/library/email.message.rst
index f1806a0..5e0509f 100644
--- a/Doc/library/email.message.rst
+++ b/Doc/library/email.message.rst
@@ -178,7 +178,7 @@
.. method:: __contains__(name)
- Return true if the message object has a field named *name*. Matching is
+ Return ``True`` if the message object has a field named *name*. Matching is
done without regard to case and *name* does not include the trailing
colon. Used for the ``in`` operator. For example::