agentic-retrieval-pipeline-example needs better instructions on "configure access"

[hustcalm]

https://github.com/Azure-Samples/azure-search-python-samples/blob/main/agentic-retrieval-pipeline-example/agent-example.ipynb does not provide clear guidelines on "configure access" compared to https://github.com/Azure-Samples/azure-search-python-samples/blob/main/Quickstart-Agentic-Retrieval/quickstart-agentic-retrieval.ipynb, especially on (looks like Search Index Data Contributor is enough for the sample):

Assign the following roles to yourself.

• Search Service Contributor
• Search Index Data Contributor
• Search Index Data Reader

[mattgotteiner]

Thanks, we'll be sure to update that