Update Doc/library/enum.rst

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

Author: guoci

Doc/library/enum.rst

@@ -157,7 +157,7 @@ Module Contents
 
       Like built-in :func:`bin`, except negative values are represented in
       two's complement, and the leading bit always indicates sign
-      (0=positive, 1=negative).
+      (``0`` implies positive, ``1`` implies negative).
 
 
 .. versionadded:: 3.6  ``Flag``, ``IntFlag``, ``auto``