Correct grammar mistake in re.rst. (GH-9745)

(cherry picked from commit 7dfbd4967121ef6ecabe3fd53a430fd949f405fd)

Co-authored-by: Andrés Delfino <adelfino@gmail.com>
diff --git a/Doc/library/re.rst b/Doc/library/re.rst
index 8228d91..cc3516a 100644
--- a/Doc/library/re.rst
+++ b/Doc/library/re.rst
@@ -204,7 +204,7 @@
      Standard #18`_ might be added in the future.  This would change the
      syntax, so to facilitate this change a :exc:`FutureWarning` will be raised
      in ambiguous cases for the time being.
-     That include sets starting with a literal ``'['`` or containing literal
+     That includes sets starting with a literal ``'['`` or containing literal
      character sequences ``'--'``, ``'&&'``, ``'~~'``, and ``'||'``.  To
      avoid a warning escape them with a backslash.