chore: update readme

README.md

@@ -17,16 +17,16 @@ DocArray is a library for nested, unstructured, multimodal data in transit, incl
 
 🚪 **Door to cross-/multi-modal world**: super-expressive data structure for representing complicated/mixed/nested text, image, video, audio, 3D mesh data. The foundation data structure of [Jina](https://github.com/jina-ai/jina), [CLIP-as-service](https://github.com/jina-ai/clip-as-service), [DALL·E Flow](https://github.com/jina-ai/dalle-flow), [DiscoArt](https://github.com/jina-ai/discoart) etc.
 
-🐍 **Pythonic experience**: designed to be as easy as a Python list. If you know how to Python, you know how to DocArray. Intuitive idioms and type annotation simplify the code you write.
-
 🧑‍🔬 **Data science powerhouse**: greatly accelerate data scientists' work on embedding, k-NN matching, querying, visualizing, evaluating via Torch/TensorFlow/ONNX/PaddlePaddle on CPU/GPU.
 
-🚡 **Data in transit**: optimized for network communication, ready-to-wire at anytime with fast and compressed serialization in Protobuf, bytes, base64, JSON, CSV, DataFrame. 
+🚡 **Data in transit**: optimized for network communication, ready-to-wire at anytime with fast and compressed serialization in Protobuf, bytes, base64, JSON, CSV, DataFrame. Perfect for streaming and out-of-memory data.
 
-🎡 **Scale to big data**: handle out-of-memory data via on-disk document store while staying with exact same API experience. Supporting classic databases and vector databases to enable faster nearest neighbour search.
+🔎 **One-stop k-NN**: Unified and consistent API for mainstream vector databases that allows nearest neighboour search including Elasticsearch, Redis, ANNLite, Qdrant, Weaviate.
 
 👒 **For modern apps**: GraphQL support makes your server versatile on request and response; built-in data validation and JSON Schema (OpenAPI) help you build reliable webservices.
 
+🐍 **Pythonic experience**: designed to be as easy as a Python list. If you know how to Python, you know how to DocArray. Intuitive idioms and type annotation simplify the code you write.
+
 🛸 **Integrate with IDE**: pretty-print and visualization on Jupyter notebook & Google Colab; comprehensive auto-complete and type hint in PyCharm & VS Code.
 
 Read more on [why should you use DocArray](https://docarray.jina.ai/get-started/what-is/) and [comparison to alternatives](https://docarray.jina.ai/get-started/what-is/#comparing-to-alternatives).