chore: move single-instance plugin

plugins/single-instance/examples/emit-event/README.md

@@ -0,0 +1,25 @@
+# Tauri Plugin single-instance
+## Emit Event Example
+
+To build and test in development mode run the following:
+
+```sh
+# change to this example directory
+npm install
+npm run tauri dev
+
+# or if tauri is installed globally
+
+cargo tauri dev
+```
+
+While the above is running, in a separate terminal window execute the debug target app
+
+```sh
+# on linux
+./src-tauri/target/debug/emit-event-app cyan # any css background color should work
+./src-tauri/target/debug/emit-event-app "#888" # including hex
+
+# on windows
+.\src-tauri\target\debug\emit-event-app.exe cyan
+```