add yaml

Signed-off-by: kosuke55 <[email protected]>

vehicle/vehicle_info_util/Readme.md

@@ -23,7 +23,7 @@ We have implemented a versioning system for the `vehicle_info.param.yaml` file t
 - For subsequent updates, continue incrementing the version number in accordance with the changes made.
   - Discuss how to increment version depending on the amount of changes made to the file.
 
-```
+```yaml
 /**:
   ros__parameters:
     # version: 0.1.0 # Uncomment and update this line for future format changes.