Host vue-codemod playground online

### Is your feature request related to a problem? Please describe.
To run vue-codemod playground, users have to clone this package, run `yarn playground` and check `http://localhost:3000`

### Describe the solution you'd like
Host vue-codemod playground online (like GitHub pages)

### Additional context
Playground was added in https://github.com/vuejs/vue-codemod/pull/2