Update Doc/library/string.rst

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

Author: skirpichev

Doc/library/string.rst

@@ -427,7 +427,7 @@ When no explicit alignment is given, preceding the *width* field by a zero
 (``'0'``) character enables sign-aware zero-padding for numeric types,
 excluding :class:`complex`.  This is equivalent to a *fill* character of
 ``'0'`` with an *alignment* type of ``'='``.  If digit group separators of the
-integral part of a number are used (as specified either by ``','`` or ``'_'``
+integral part of a number are used (as specified either by the ``','`` or ``'_'``
 option), they are also placed between leading zeros.
 
 .. versionchanged:: 3.10