add decorator to define options

[thatkookooguy]

FEATURE

Currently, you can define parameters for each function and how each parameter will behave. but what about flags? (e.g. --username neil or -u neil)

Suggested behavior:

@cliOptions([
  ['username', 'The username to get data for']
])
static getUser(arg1, arg2, options) {
  if (!options.username) { throw new Error('username is required') }

  console.log(`this is our username: ${ options.username }`);
}

it will automatically add those flags to this specific function and attach it to the end of the arguments list (like a callback for example).