Add a "Running the Glojure tests" section

[ingydotnet]

No description provided.

[CLAassistant]

All committers have signed the CLA.

[jeaye]

Hey Ingy! Thanks for the interest in this test suite for gloat. It's nice to see you have such good results already.

I would really like to get gloat added to CI, rather than linked to from the readme. That's how every other dialect (CLR, CLJS, bb, basilisp, jank) has done it and it shows a level of commitment to Clojure compatibility which I think is part of the unifying goal of this test suite.

Does that align with your goals?

[ingydotnet]

I can add the CI config to this PR.

[dgr]

This PR won't apply cleanly now since it updates README.md and most information about dialects has been moved out of that file into separate dialect-specific files in doc/. I would rework this PR based on the current version of the main branch.