Add JSON output example to debug docs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Mike McCarty <mmccarty@nvidia.com>

Author: mmccarty

docs/source/api/debug.rst

@@ -20,6 +20,10 @@ for troubleshooting RAPIDS installations.
 
 Output is either a Rich-formatted console table or JSON (``--json``).
 
+Example:
+
+``rapids debug --json > "<name-output-file>.json"``
+
 API
 ---