Improve program name in website --help

Take basename of argv[0] so the help message is a little more succinct.

scripts/website

@@ -6,6 +6,7 @@ A Python interface to my personal website, Erynwells.me.
 '''
 
 import argparse
+import os.path as osp
 from typing import List
 from erynwells_me.scripting import Command
 from erynwells_me.weeknotes import WeeknotesCommand
@@ -31,7 +32,8 @@ def parse_args(commands: List[Command], argv, *a, **kw):
 
 
 def main(argv):
-    args = parse_args(COMMANDS, argv[1:], prog=argv[0])
+    program_name = osp.basename(argv[0])
+    args = parse_args(COMMANDS, argv[1:], prog=program_name)
     return args.handler(args)