Docs on website for `flag` are broken

[lgarron]

This repo lists https://cmd-ts.now.sh/ as its URL, which redirects to https://cmd-ts.vercel.app/

https://cmd-ts.vercel.app/parsers/flags.html includes this example, which causes inscrutable type-checking errors:

import { command, boolean, flag } from 'cmd-ts';

const myFlag = option({
  type: boolean,
  long: 'my-flag',
  short: 'f',
});

const cmd = command({
  name: 'my flag',
  args: { myFlag },
});

This repo seems to contain more up-to-date docs, but they are broken in a different way (seemingly due to the lack of a specified handler:

https://github.com/Schniz/cmd-ts/blob/e6759073041f19e07906087ddcc15a416361ec7c/docs/parsers/flags.md?plain=1

[lgarron]

Partial duplicate of #197, although I think the handler issue still needs a fix.