message: feat(cli): add --version option
diff: #!/usr/bin/env node
  +import { command, parse, version } from 'commander';
  -import { command, parse } from 'commander';
  +// @ts-ignore
  +import packageJson from '../package.json';
  +
  +// commands
  import { dev } from './commands/dev';
  import { lint } from './commands/lint';
  import { test } from './commands/jest';
  @@ -11,6 +15,8 @@ import { changelog } from './commands/changelog';
  import { buildSite } from './commands/build-site';
  import { commitLint } from './commands/commit-lint';
  +version(`@vant/cli ${packageJson.version}`);
  +
  command('dev')
  .description('Run webpack dev server')
  .action(dev);
  