[positioner] handleIconState in JS (#1822)

* [positioner] handleIconState in JS

* update readme

* fix change file version

* fixes

---------

Co-authored-by: Lucas Nogueira <lucas@tauri.app>

plugins/positioner/README.md

@@ -58,6 +58,7 @@ fn main() {
         .plugin(tauri_plugin_positioner::init())
         // This is required to get tray-relative positions to work
         .setup(|app| {
+            // note that this will create a new TrayIcon
             TrayIconBuilder::new()
                 .on_tray_icon_event(|app, event| {
                     tauri_plugin_positioner::on_tray_event(app.app_handle(), &event);
@@ -70,6 +71,40 @@ fn main() {
 }
 ```
 
+Alternatively, you may handle the tray events through JavaScript. Register the plugin as previously noted.
+
+```rust
+fn main() {
+    tauri::Builder::default()
+        .plugin(tauri_plugin_positioner::init())
+        .run(tauri::generate_context!())
+        .expect("error while running tauri application");
+}
+```
+
+And in JavaScript, the `action` passed to the TrayIcon should include the handler.
+
+```javascript
+import {
+  moveWindow,
+  Position,
+  handleIconState,
+} from "@tauri-apps/plugin-positioner";
+
+const action = async (event: TrayIconEvent) => {
+  // add the handle in the action to update the state
+  await handleIconState(event);
+  if ("click" in event) {
+    const { click } = event;
+    // note this option requires enabling the `tray-icon`
+    //   feature in the Cargo.toml
+    await moveWindow(Position.TrayLeft);
+  }
+};
+
+const tray = await TrayIcon.new({ id: "main", action });
+```
+
 Afterwards all the plugin's APIs are available through the JavaScript guest bindings:
 
 ```javascript