chore(example) add README, closes #635 (#689)

* chore(example) add README closes #635

* chore(example) add rust-only way to build the communication example

tauri/examples/communication/README.md

@@ -0,0 +1,32 @@
+# Communication example
+This example demonstrates Tauri's API capabilities. It's used as the main validation app, serving as the testbed of our development process.
+In the future, this app will be used on Tauri's integration tests.
+
+![App screenshot](./screenshot.png?raw=true)
+
+## Running the example
+- Install dependencies
+```bash
+# with yarn
+$ yarn
+# with npm
+$ npm install
+```
+
+- Compile the app
+```bash
+# with yarn
+$ yarn build
+# with npm
+$ npm run build
+# alternatively, if you setup the environment variables, you can build it without Node.js:
+$ cd ../../..
+$ . .scripts/init_env.sh
+$ cd ./tauri/examples/communication
+$ cargo build --features no-server
+```
+
+- Run the app
+```bash
+$ ./src-tauri/target/release/app
+```

tauri/examples/communication/package.json

@@ -4,7 +4,11 @@
   "description": "A Tauri example showcasing the JS-Rust communication",
   "main": "index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "build": "tauri build"
   },
-  "private": true
+  "private": true,
+  "dependencies": {
+    "tauri": "link:../../../cli/tauri.js"
+  }
 }