Add documentation for ConfigFile path and add printing loaded config (or path) to debug

[stacksjb]

I added a commitlint.config.mjs file to my repo under ./github/workflows/config/commitlint.config.mjs

However, it was never picked up, even when that path was specified under configFile emanually

After lots of testing, I found that it appears commitlint only pulls a config file from the root directory (no other location), even though you can manually specify the location.

1. Is this expected?
2. I didn't see the loaded config path printed in the CI output (even when running with debug) - this would have been very helpful (or even "Using default config") - could this be added?