Add basic ElixirKit readme (#2930)

elixirkit/README.md

@@ -1 +1,61 @@
 # ElixirKit
+
+ElixirKit helps running Elixir alongside native desktop applications on macOS and Windows.
+
+🚧 ElixirKit is experimental and subject to change without notice.
+
+See [demo](demo) project, in particular [demo/lib/demo.ex](demo/lib/demo.ex),
+[demo/rel/appkit](demo/rel/appkit), and [demo/rel/winforms](demo/rel/winforms).
+
+## ElixirKit for macOS (Swift)
+
+- `ElixirKit.API.isRunning: Bool`
+  - Returns whether the Elixir runtime is currently running
+
+- `ElixirKit.API.start(name: String, logPath: String?, readyHandler: () -> Void, terminationHandler: ((Process) -> Void)?) -> Void`
+  - Starts the Elixir runtime
+
+- `ElixirKit.API.publish(_ name: String, _ data: String) -> Void`
+  - Publishes an event to the Elixir runtime
+
+- `ElixirKit.API.stop() -> Void`
+  - Stops the Elixir runtime
+
+- `ElixirKit.API.waitUntilExit() -> Void`
+  - Blocks until the Elixir runtime exits
+
+- `ElixirKit.API.addObserver(queue: OperationQueue?, using: ((String, String)) -> Void) -> Void`
+  - Adds an observer for events from the Elixir runtime
+
+## ElixirKit for Windows (C#)
+
+- `ElixirKit.API.HasExited: bool` - Indicates whether the Elixir runtime has exited
+
+- `ElixirKit.API.IsMainInstance(string id) -> bool`
+  - Checks if the current app is the main instance
+
+- `ElixirKit.API.Start(string name, ReadyHandler ready, ExitHandler? exited = null, string? logPath = null) -> void`
+  - Starts the Elixir runtime
+
+- `ElixirKit.API.Publish(string name, string data) -> void`
+  - Publishes an event to the Elixir runtime
+
+- `ElixirKit.API.Subscribe(EventHandler handler) -> void`
+  - Subscribes to events from the Elixir runtime
+
+- `ElixirKit.API.Stop() -> int`
+  - Stops the Elixir runtime
+  - Returns exit code
+
+- `ElixirKit.API.WaitForExit() -> int`
+  - Blocks until the Elixir runtime exits
+  - Returns exit code
+
+- `ElixirKit.ReadyHandler:() -> void`
+  - Callback for when the runtime is ready
+
+- `ElixirKit.ExitHandler:(int ExitCode) -> void`
+  - Callback for when the runtime exits
+
+- `ElixirKit.EventHandler:(string Name, string Data) -> void`
+  - Callback for handling events from the runtime