message: docs(lambda-at-edge): add initial documentation
diff: -### AWS Lambda@Edge toolbox to help you deploy serverless next.js applications to CloudFront
  +### AWS Lambda@Edge library to help you deploy serverless next.js applications to CloudFront
  -TODO: Contents
  +This library was created to decouple the core logic of creating serverless rendered next.js applications on the Cloud agnostic of a specific provider. In other words, this library could be used to deploy via serverles components, AWS CDK, or any other providers you'd like.
  +
  +## Usage
  +
  +```
  +const path = require('path');
  +const { Builder } = require("@sls-next/lambda-at-edge");
  +
  +const nextConfigDir = '/dir/to/my/nextapp';
  +const outputDir = path.join(nextConfigDir, ".serverless_nextjs"),
  +
  +const builder = new Builder(
  + nextConfigDir,
  + outputDir,
  + {
  + cmd: './node_modules/.bin/next',
  + cwd: process.cwd(),
  + env: {},
  + args: ['build']
  + }
  +);
  +
  +await builder.build();
  +```
  +
  +After running the above, the output directory will contain the Lambda@Edge handlers necessary to server side render at the edge.
  +
  +```
  +/dir/to/my/next-app/.serverless_nextjs/
  +
  + > default-lambda
  + > manifest.json
  + > pages/
  + > node_modules/next-aws-cloudfront/index.js
  + > index.js # handler
  +
  + > api-lambda
  + > manifest.json
  + > pages/api/
  + > node_modules/next-aws-cloudfront/index.js
  + > index.js # handler
  +```
  +
  +The handlers need to be attached to the `origin-request` trigger of CloudFront. The `api-lambda` edge function should be attached to a CloudFront behaviour that only triggers in the event of `/api/*` requests.
  +
  +### TODO:
  +
  +- Provisioning and configuration of the CloudFront distribution
  +- Create a separate utility to clean up unused Lambda@Edge functions that were previously attached to a CloudFront distribution
  