change synthetic_rag title

Generating Synthetic Dataset for RAG -> Use LLM to generate data to train a new generation of LLM/retrieval/other models

This article actually has little to do with rag

Locate the article currently titled “Generating Synthetic Dataset for RAG” and review its surrounding content. Rename the article to reflect that it covers using LLMs to generate training data for retrieval and other models, then verify the new title accurately matches the article.

Written by the indexing model from the issue text.