Add debug to justfile --check

NB. It might be possible to do this through an optional argument
in `just` but I am not clear on this right now.

Author: ross-spencer

justfile

@@ -74,3 +74,7 @@ clean:
 # Check the registry entries are correct.
 check:
    python jsonid.py --check
+
+# Check the registry entries are correct (DEBUG).
+check-debug:
+   python jsonid.py --check --debug