[1.7.x] Fixed formatting in docs/ref/templates/builtins.txt

Backport of 6023312 from master

docs/ref/templates/builtins.txt

@@ -2452,24 +2452,24 @@ If ``value`` is ``Joel is a slug``, the output would be::
 yesno
 ^^^^^
 
-Maps values for true, false and (optionally) None, to the strings "yes", "no",
-"maybe", or a custom mapping passed as a comma-separated list, and
+Maps values for ``True``, ``False``, and (optionally) ``None``, to the strings
+"yes", "no", "maybe", or a custom mapping passed as a comma-separated list, and
 returns one of those strings according to the value:
 
 For example::
 
     {{ value|yesno:"yeah,no,maybe" }}
 
-==========  ======================  ==================================
+==========  ======================  ===========================================
 Value       Argument                Outputs
-==========  ======================  ==================================
+==========  ======================  ===========================================
 ``True``                            ``yes``
 ``True``    ``"yeah,no,maybe"``     ``yeah``
 ``False``   ``"yeah,no,maybe"``     ``no``
 ``None``    ``"yeah,no,maybe"``     ``maybe``
-``None``    ``"yeah,no"``           ``"no"`` (converts None to False
-                                    if no mapping for None is given)
-==========  ======================  ==================================
+``None``    ``"yeah,no"``           ``no`` (converts ``None`` to ``False``
+                                    if no mapping for ``None`` is given)
+==========  ======================  ===========================================
 
 Internationalization tags and filters
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