Update the naming conventions for parameters in launch files

[xmfcx]

Checklist

• [X] I've read the contribution guidelines.
• [X] I've searched other issues and no duplicate issues were found.
• [X] I've agreed with the maintainers that I can plan this task.

Description

Follow up from https://github.com/autowarefoundation/autoware-documentation/pull/223

Purpose

Update the naming conventions for namespaces and launch files following discussion in https://github.com/orgs/autowarefoundation/discussions/3171

Possible approaches

Update the documentation following up from https://github.com/autowarefoundation/autoware-documentation/pull/223

Definition of done

PR is merged covering the updates in the discussion.

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity.