Merge #8158: add missing 'description' description to optparse docstring.

Lib/optparse.py

@@ -1120,6 +1120,11 @@ class OptionParser (OptionContainer):
       prog : string
         the name of the current program (to override
         os.path.basename(sys.argv[0])).
+      description : string
+        A paragraph of text giving a brief overview of your program.
+        optparse reformats this paragraph to fit the current terminal
+        width and prints it when the user requests help (after usage,
+        but before the list of options).
       epilog : string
         paragraph of help text to print after option help