docs: updated docs.

Author: melvinlee

README.md

@@ -1 +1,46 @@
-# aws-lambda-express-restapi
+# AWS Lambda REST API using Serverless, Express and Nodejs
+
+Demostrate how to use the popular Node web framework Express.js to deploy a Serverless REST API. This means you can use your existing code + the vast Express.js ecosystem and benefits of Serverless. 
+
+## Getting Started
+
+We'll install the `serverless-http` framework
+
+```sh 
+$ npm install --save express serverless-http
+```
+
+The `serverless-http` package is a handy piece of middleware that handles the interface between your Node.js application and the specifics of API Gateway.
+
+Let's create an index.js file that has our application code:
+
+```js
+// index.js
+
+const serverless = require('serverless-http');
+const express = require('express')
+const app = express()
+
+app.get('/', function (req, res) {
+  res.send('Hello World!')
+})
+
+module.exports.handler = serverless(app);
+```
+
+To get this application deployed, let's create a `serverless.yml` in our working directory:
+
+```yml
+# serverless.yml
+
+functions:
+  app:
+    handler: index.handler
+    events:
+      - http: ANY /
+      - http: 'ANY {proxy+}'
+```
+
+This is a pretty basic configuration. We've created one function, app, which uses the exported handler from our index.js file. Finally, it's configured with some HTTP triggers.
+
+We've used a very broad path matching so that all requests on this domain are routed to this function. All of the HTTP routing logic will be done inside the Express application.