[DOC] Add info about Data Prepper in Tools overview topic

[hdhalter]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request and all versions that are affected.
In our Tools overview topic, we don't mention Data Prepper. Let's add a summary of Data Prepper here: https://opensearch.org/docs/latest/tools/index/#agents-and-ingestion-tools.

Also, please check this property, as it may have been removed in 2.0: if "override_main_response_version": true

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

[hdhalter]

Hi Nate, can you please add a summary about Data Prepper? I sent a message to marketing to see if they have some messaging around it.

[hdhalter]

Marketing will have some content on DP positioning in about 2+ weeks. For now, we should at least point to the Data Prepper documentation.