reorder and fix links

Signed-off-by: M. Fatih Cırıt <mfc@leodrive.ai>

Author: M. Fatih Cırıt

planning/.pages

@@ -76,9 +76,8 @@ nav:
     - 'RTC Interface': planning/rtc_interface
   - 'Additional Tools':
     - 'RTC Replayer': planning/rtc_replayer
-    - 'Planning Debug Tools':
-      - 'About Planning Debug Tools': https://github.com/autowarefoundation/autoware_tools/tree/main/planning_debug_tools
-      - 'Stop Reason Visualizer': https://github.com/autowarefoundation/autoware_tools/tree/main/planning_debug_tools/doc-stop-reason-visualizer
+    - 'Planning Debug Tools': https://github.com/autowarefoundation/autoware_tools/tree/main/planning/planning_debug_tools
+      - 'Stop Reason Visualizer': https://github.com/autowarefoundation/autoware_tools/blob/main/planning/planning_debug_tools/doc-stop-reason-visualizer.md
     - 'Planning Test Utils': planning/planning_test_utils
     - 'Planning Topic Converter': planning/planning_topic_converter
     - 'Planning Validator': planning/planning_validator