Add public-dir, host and port to manifest

[Richard87]

Hi!

We are serving a Symfony PHP application with Caddy, and Symfony reads this manifest file and serves the correct assets, this works perfectly!

But, in development, I would love to serve the assets directly with parcel on its own port, and not trough Caddy, but parcel-reporter-bundle-manifest doesnt include the schema/host/port when using parcel serve.

This is different than webpack dev-server works, would you accept a PR to include this information?