README updated

Author: anijitsao

README.md

@@ -1 +1,73 @@
-# simple-aws-lambda-mongodb
+# simple-aws-lambda-mongodb
+
+This example demonstrates how to deploy a [NodeJS](https://nodejs.org/en/docs/) function running on [AWS Lambda](https://aws.amazon.com/lambda/) using the traditional [Serverless](https://www.serverless.com/framework/docs/providers/aws/guide/intro) Framework. The deployed function works with multiple type of event definitions.
+
+This Example works with both `cron` events and `httpApi` events. 
+
+When deployed the [AWS Lambda](https://aws.amazon.com/lambda/) function sends Emails by using [AWS Simple Email Service(SES)](https://aws.amazon.com/ses/). Now the Emails can be sent either by an [AWS HTTP API](https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-develop.html) event or by a `cron` like fashion to a stipulated time interval set in the [AWS Cloudformation](https://aws.amazon.com/cloudformation/) Stack.
+
+All *logs* for the function is kept in [AWS Cloudwatch](https://aws.amazon.com/cloudwatch/) i.e *persistent*. [AWS EventBridge](https://aws.amazon.com/about-aws/whats-new/2019/07/introducing-amazon-eventbridge/) is used to handle **both** types of `schedule` and `http` events.
+
+To use the code in this example you **must** have an valid [AWS account](https://aws.amazon.com/account/) and necessary [AWS IAM](https://aws.amazon.com/iam/) roles and programmatic access to an user.
+
+## Features
+1. [AWS Lambda](https://aws.amazon.com/lambda/) function using [NodeJS](https://nodejs.org/en/docs/)
+2. Function is using latest version of [AWS SDK JavaScript v3](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/welcome.html) with all **ES6+**  syntaxes like Promises, `async/await`
+
+<ol start="3">
+  <li>
+     Function are deployed using <a href="https://www.serverless.com/framework/docs/providers/aws/guide/intro">Serverless</a> Framework.
+  </li>  
+  <li>
+    <code>serverless.json</code> is used for deployment configuration instead of <code>serverless.yml</code>.
+  </li>  
+  <li>
+    All the deployment is created in <a href="https://aws.amazon.com/s3/">AWS S3</a> to store the <code>.zip</code> of the function code and <a href="https://aws.amazon.com/cloudformation/">AWS CloudFormation</a> Stack.
+  </li>  
+</ol>  
+
+
+6. **Two** types of events are supported `httpAPi` and `schedule`
+7. [AWS HTTP API](https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-develop.html) are using [AWS API GateWay](https://aws.amazon.com/api-gateway/)
+
+<ol start="8">
+  <li> All Emails are sent using <a href="https://aws.amazon.com/ses/">AWS Simple Email Service(SES)</a>. For that purpose valid <i>Identities</i> must be created.</li>
+  <li>  Email Templates are created using <a href="https://www.w3schools.com/html/default.asp">HTML5</a> and <a href="https://www.w3schools.com/css/">CSS3</a></li> 
+  <li> This APIs can also be consumed by any <b>Frontend Application</b>.</li> 
+</ol>  
+
+11. [NPM](https://www.npmjs.com/) dependencies are used for various purposes.
+12. **Custom Headers** are added with the response for *obvious security* reasons.
+
+## Usage
+
+First clone the repo
+
+```bash
+$ git clone git@github.com:anijitsahu/simple-aws-lambda-ses-cron.git
+```
+Install all the necessary dependencies by going inside the directory
+
+```bash
+$ cd simple-aws-lambda-ses-cron.git
+$ npm install
+```
+
+
+### Deployment
+
+In order to deploy the example, you need to run the following command:
+
+```
+$ serverless deploy
+```
+
+### Invocation
+
+After successful deployment, you can invoke the deployed function. 
+All the `cron` events will invoke the deployed functions in stipulated time interval. 
+
+However, to call using `httpApi` you can use any REST Client like [Talend API Tester](https://chrome.google.com/webstore/detail/talend-api-tester-free-ed/aejoelaoggembcahagimdiliamlcdmfm?hl=en) with the `url` and *HTTP Verbs* as shown in Terminal after using `serverless deploy`.
+
+
+