Update with new Quickstart information

Author: rachmari

README.md

@@ -1,13 +1,21 @@
-This is the sample project built by following the "[Building Your First GitHub App](https://developer.github.com/apps/building-your-first-github-app)" Quickstart guide on developer.github.com.
+This is an example GitHub App that adds a label to all new issues opened in a repository. You can follow the "[Building your first GitHub App](https://developer.github.com/apps/quickstart-guide/building-your-first-github-app)" Quickstart guide on developer.github.com to learn how to build the app code in `server.rb`.
 
-It consists of two different servers: `server.rb` (boilerplate) and `advanced_server.rb` (completed project).
+This project listens for webhook events and uses the Octokit.rb library to make REST API calls. This example project consists of two different servers:
+* `template_server.rb` (GitHub App template code)
+* `server.rb` (completed project)
 
-## Install and run
+To learn how to set up a template GitHub App, follow the "[Configuring a GitHub App](https://developer.github.com/apps/quickstart-guide/configuring-ast-github-app)" Quickstart guide on developer.github.com.
+
+## Install
 
 To run the code, make sure you have [Bundler](http://gembundler.com/) installed; then enter `bundle install` on the command line.
 
-* For the boilerplate project, enter `ruby server.rb` on the command line.
+## Set environment variables
+
+1. Create a copy of the `.env-example` file called `.env`.
+2. Add your GitHub App's private key, app ID, and webhook secret to the `.env` file.
 
-* For the completed project, enter `ruby advanced_server.rb` on the command line.
+## Run the server
 
-Both commands will run the server at `localhost:3000`.
+1. Run `ruby template_server.rb` or `ruby server.rb` on the command line.
+1. View the default Sinatra app at `localhost:3000`.