Fix markup of the synopsis along with changing to state what is in the
module and not as a definition of what an enumeration is.
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index 92c6bfb..ae0498c 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -2,8 +2,8 @@
 ========================================
 
 .. module:: enum
-.. :synopsis: enumerations are sets of symbolic names bound to unique, constant
-  values.
+   :synopsis: Implementation of an enumeration class.
+
 .. :moduleauthor:: Ethan Furman <ethan@stoneleaf.us>
 .. :sectionauthor:: Barry Warsaw <barry@python.org>,
 .. :sectionauthor:: Eli Bendersky <eliben@gmail.com>,