Clean up the list of allowed command-line flags.

Doc/using/cmdline.rst

@@ -21,7 +21,7 @@ Command line
 
 When invoking Python, you may specify any of these options::
 
-    python [-bdEiOsStuUvxX?] [-c command | -m module-name | script | - ] [args]
+    python [-bBdEhiOsSuvVWx?] [-c command | -m module-name | script | - ] [args]
 
 The most common use case is, of course, a simple invocation of a script::