feat: add autoware_rosbag2_anonymizer usage

[StepTurtle]

Description

This PR updates the dataset documentation and adds instructions for the data anonymizer tool.

Related issue:

• Create a rosbag anonymizer tool autoware#4551

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[github-actions]

Documentation URL: https://autowarefoundation.github.io/autoware-documentation/pr-557/
Modified URLs:

• https://autowarefoundation.github.io/autoware-documentation/pr-557/datasets/data-anonymization/