Minimal how-to guide for component model schemas

[devidw]

Based on trpc#417 (comment) it looks like this fork does support the definition of model schemas that go into the components section of the final openapi doc?

I read over the readme but could not find any hints how this fork makes this available as a library user, could you provide a minimal example on how to do this?

Much appreciated!

[devidw]

Ended up implementing it myself: https://github.com/devidw/trpc-openapi