docs(vehicle_info): add docs for versioning

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

vehicle/vehicle_info_util/Readme.md

@@ -7,6 +7,35 @@ This package is to get vehicle info parameters.
 ### Description
 
 In [here](https://autowarefoundation.github.io/autoware-documentation/main/design/autoware-interfaces/components/vehicle-dimensions/), you can check the vehicle dimensions with more detail.
+The current format supports only the Ackermann model and will not be extended to other models in the future. This file defines the model assumed in autoware path planning, control, etc. and does not represent the exact physical model. If a model other than the Ackermann model is used, it is assumed that a vehicle interface will be designed to change the control output for the model.
+
+### Versioning Policy
+
+We have implemented a versioning system for the `vehicle_info.param.yaml` file to ensure clarity and consistency in file format across different versions of Autoware and its external applications. Please see [discussion](https://github.com/orgs/autowarefoundation/discussions/4050 for the details).
+
+#### How to Operate
+
+- The current file format is set as an unversioned base version (`version:` field is commented out).
+- For the next update involving changes (such as additions, deletions, or modifications):
+  - Uncomment and update the version line at the beginning of the file.
+  - Initiate versioning by assigning a version number, starting from `0.1.0`. Follow the semantic versioning format (MAJOR.MINOR.PATCH).
+  - Update this Readme.md too.
+- 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.
+
+```
+/**:
+  ros__parameters:
+    # version: 0.1.0 # Uncomment and update this line for future format changes.
+    wheel_radius: 0.383
+    ...
+```
+
+#### Why Versioning?
+
+- Consistency Across Updates: Implementing version control will allow accurate tracking of changes over time and changes in vehicle information parameters.
+- Clarity for External Applications: External applications that depend on `vehicle_info.param.yaml` need to reference the correct file version for optimal compatibility and functionality.
+- Simplified Management for Customized Branches: Assigning versions directly to the `vehicle_info.param.yaml` file simplifies management compared to maintaining separate versions for multiple customized Autoware branches. This approach streamlines version tracking and reduces complexity.
 
 ### Scripts
 

vehicle/vehicle_info_util/config/vehicle_info.param.yaml

@@ -1,5 +1,6 @@
 /**:
   ros__parameters:
+    # version: 0.1.0 # uncomment this line in the next update of this file format
     wheel_radius: 0.39
     wheel_width: 0.42
     wheel_base: 2.74 # between front wheel center and rear wheel center