added serverles example

README.md

@@ -24,4 +24,4 @@ const ewelink = require('ewelink-api');
 })();
 ```
 
-Check `demo/example.js` for more examples.
+Check `demo/` directory for more examples.

demo/serverless.js

@@ -0,0 +1,25 @@
+const ewelink = require('../main');
+
+(async () => {
+  /* first request: get access token and api key */
+  const conn1 = new ewelink({
+    email: '<your ewelink email>',
+    password: '<your ewelink password>',
+  });
+  const login = await conn1.login();
+  const accessToken = login.at;
+
+  /* second request: use access token to request devices */
+  const conn2 = new ewelink({ at: accessToken });
+  const devices = await conn2.getDevices();
+  console.log(devices);
+
+  /* third request: use access token to request specific device info */
+  const conn3 = new ewelink({ at: accessToken });
+  const device = await conn3.getDevice('<your device id>');
+  console.log(device);
+
+  /* fourth request: use access token to toggle specific device info */
+  const conn4 = new ewelink({ at: accessToken });
+  await conn4.toggleDevice('<your device id>');
+})();