docs: fix broken links

examples/README.md

@@ -29,8 +29,8 @@ Please make sure you have created a TiDB Serverless cluster with vector support
 - [Image Search](./image_search/README.md): use the OpenAI CLIP model to generate vectors for image and text.
 - [LlamaIndex RAG with UI](./llamaindex-tidb-vector-with-ui/README.md): use the LlamaIndex to build an [RAG(Retrieval-Augmented Generation)](https://docs.llamaindex.ai/en/latest/getting_started/concepts/) application.
 - [Chat with URL](./llamaindex-tidb-vector/README.md): use LlamaIndex to build an [RAG(Retrieval-Augmented Generation)](https://docs.llamaindex.ai/en/latest/getting_started/concepts/) application that can chat with a URL.
-- [GraphRAG](./examples/graphrag-demo/README.md): 20 lines code of using TiDB Serverless to build a Knowledge Graph based RAG application.
-- [GraphRAG Step by Step Tutorial](./examples/graphrag-step-by-step-tutorial/README.md): Step by step tutorial to build a Knowledge Graph based RAG application with Colab notebook. In this tutorial, you will learn how to extract knowledge from a text corpus, build a Knowledge Graph, store the Knowledge Graph in TiDB Serverless, and search from the Knowledge Graph.
+- [GraphRAG](./graphrag-demo/README.md): 20 lines code of using TiDB Serverless to build a Knowledge Graph based RAG application.
+- [GraphRAG Step by Step Tutorial](./graphrag-step-by-step-tutorial/README.md): Step by step tutorial to build a Knowledge Graph based RAG application with Colab notebook. In this tutorial, you will learn how to extract knowledge from a text corpus, build a Knowledge Graph, store the Knowledge Graph in TiDB Serverless, and search from the Knowledge Graph.
 
 ## Real World Applications