Add README with HAL ML API overview and architecture diagram

README.md

@@ -0,0 +1,48 @@
+# HAL ML API Overview
+
+## Introduction
+
+The HAL ML API provides an interface for [Tizen's higher-level Machine Learning API](https://docs.tizen.org/application/native/guides/machine-learning/overview) to interact with various hardware acceleration devices (e.g., NPUs, GPUs, DSPs) via [HAL ML Accelerator Backends](https://github.com/nnstreamer/hal-backend-ml-accelerator). **Users would not use this directly**, it is used in implementation of [NNStreamer](https://github.com/nnstreamer/nnstreamer)'s `tensor_filter` sub-plugin which is backend of Tizen ML API.
+
+## Architecture
+
+```mermaid
+graph TD
+    subgraph TF["Tizen Framework"]
+        A["Tizen ML API"]
+    end
+
+    subgraph HM["HAL API ML"]
+        D["Tizen HAL API for ML"]
+    end
+
+    subgraph HBMA["HAL Backend ML Accelerator"]
+        E["backend for each vendor"]
+    end
+
+    subgraph MA["Device"]
+        CPU
+        GPU
+        NPU
+        DSP
+    end
+
+    TF <--> HM <--> HBMA <--> MA
+
+    style TF fill:#68b,color:#000,stroke:#000
+    style HM fill:#68b,color:#000,stroke:#000
+    style HBMA fill:#68b,color:#000,stroke:#000
+    style MA fill:#68b,color:#000,stroke:#000
+
+    style A fill:#fff,color:#000,stroke:#000
+    style D fill:#fff,color:#000,stroke:#000
+    style E fill:#fff,color:#000,stroke:#000
+    style CPU fill:#fff,color:#000,stroke:#000
+    style GPU fill:#fff,color:#000,stroke:#000
+    style NPU fill:#fff,color:#000,stroke:#000
+    style DSP fill:#fff,color:#000,stroke:#000
+```
+
+## License
+
+This project is licensed under the Apache License, Version 2.0. See the [LICENSE](LICENSE) file for details.