Update the readme doc (#198)

Signed-off-by: SimFG <[email protected]>

README.md

@@ -258,7 +258,9 @@ This module is created to extract embeddings from requests for similarity search
 The **Vector Store** module helps find the K most similar requests from the input request's extracted embedding. The results can help assess similarity. GPTCache provides a user-friendly interface that supports various vector stores, including Milvus, Zilliz Cloud, and FAISS. More options will be available in the future.
   - [x] Support [Milvus](https://milvus.io/), an open-source vector database for production-ready AI/LLM applicaionts. 
   - [x] Support [Zilliz Cloud](https://cloud.zilliz.com/), a fully-managed cloud vector database based on Milvus.
+  - [x] Support [Milvus Lite](https://github.com/milvus-io/milvus-lite), a lightweight version of Milvus that can be embedded into your Python application.
   - [x] Support [FAISS](https://faiss.ai/), a library for efficient similarity search and clustering of dense vectors.
+  - [x] Support [Hnswlib](https://github.com/nmslib/hnswlib), header-only C++/python library for fast approximate nearest neighbors.
   - [ ] Support other vector databases.
 - **Cache Manager**:
 The **Cache Manager** is responsible for controlling the operation of both the **Cache Storage** and **Vector Store**.