Enable pushing WIT interfaces via CI

[t3hmrman]

It should be possible to publish a WIT interface from the component-docs repo automatically when a certain CI workflow is run.

This will likely require the following:

1. Adding bytecodealliance/component-docs to the docs:adder package list of allowed repositories
2. Creating a CI job that pushes versions of the docs/adder WIT (using the built-in github.token)