wamr-wasi-extensions: document (#4493)

Author: yamt

wamr-wasi-extensions/README.md

@@ -0,0 +1,49 @@
+# wasm-wasi-extensions
+
+wasm-wasi-extensions is a set of small static libraries
+which aims to help you build a wasm module using
+WAMR's extensions to WASIp1.
+It's expected to be used in combination with WASI-SDK.
+
+Currently it contains bindings for the following APIs:
+
+* wasi-nn
+
+* lib-socket
+
+## Usage
+
+### Preparation
+
+Place it somewhere in your `CMAKE_PREFIX_PATH`.
+
+You may want to automate the process with `FetchContent`.
+```
+set(URL https://github.com/bytecodealliance/wasm-micro-runtime/releases/download/WAMR-2.4.0/wamr-wasi-extensions-2.4.0.zip)
+
+include(FetchContent)
+FetchContent_Declare(
+    wamr-wasi-extensions
+    DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+    URL ${URL}
+)
+FetchContent_MakeAvailable(wamr-wasi-extensions)
+list(APPEND CMAKE_PREFIX_PATH ${wamr-wasi-extensions_SOURCE_DIR})
+```
+
+Now you can use cmake find_package and link it to your application.
+You can find samples in the [samples](samples) directory.
+
+### wasi-nn
+
+```
+find_package(wamr-wasi-nn REQUIRED)
+target_link_libraries(you-app wamr-wasi-nn)
+```
+
+### lib-socket
+
+```
+find_package(wamr-wasi-socket REQUIRED)
+target_link_libraries(your-app wamr-wasi-socket)
+```