feat: Add commander task for CLI option parsing

[daffl]

This pull request streamlines command line option parsing. Instead of exporting a separate command, we are now passing the generator command line options as ctx.argv which makes it much more flexible. Also adds a commander task that allows to use commander programs to parse the arguments:

import { PinionContext, commander, Command, generator } from '../../src/index.js'

interface Context extends PinionContext {
  name: string
}

const program = new Command()
  .description('A test command')
  .option('-n, --name <name>', 'Name of your project')

export const generate = (ctx: Context) =>
  generator(ctx)
    .then(commander(program))
    .then(ctx => {
      console.log(ctx.name)
    })

[marshallswain]