message: Add steps to the Express example
  Add steps for users to follow. This formats the Express example readme more like a guide or tutorial making it easier for users to add Airbrake to their app. Steps include how to adapt the example and how to run the example app locally.
diff: -# Quickstart
  +# Using Airbrake with Express.js
  -This example uses Express.js on Node.js.
  +This example Node.js application uses Express.js and sets up Airbrake to report
  +errors and performance data. To adapt this example to your app, follow these
  +steps:
  - yarn install
  - node app.js
  +#### 1. Install the package
  +```shell
  +npm install @airbrake/node
  +```
  +
  +#### 2. Include airbrake-js in your app
  +Include the required airbrake-js libraries in your `app.js`
  +
  +```js
  +const Airbrake = require('@airbrake/node');
  +const airbrakeExpress = require('@airbrake/node/dist/instrumentation/express');
  +const airbrakePG = require('@airbrake/node/dist/instrumentation/pg');
  +```
  +
  +#### 3. Configure Airbrake with your project's credentials
  +
  +```js
  +const airbrake = new Airbrake.Notifier({
  + projectId: process.env.AIRBRAKE_PROJECT_ID,
  + projectKey: process.env.AIRBRAKE_PROJECT_KEY,
  +});
  +```
  +
  +#### 4. Add the Airbrake Express middleware
  +This middleware should be added before any routes are defined.
  +
  +```js
  +app.use(airbrakeExpress.makeMiddleware(airbrake));
  +```
  +
  +#### 5. Add the Airbrake Express error handler
  +The error handler middleware should be defined last. For more info on how this
  +works, see the official
  +[Express error handling doc](http://expressjs.com/en/guide/error-handling.html).
  +
  +```js
  +app.use(airbrakeExpress.makeErrorHandler(airbrake));
  +```
  +
  +#### 6. Run your app
  +The last step is to run your app. To test that you've configured Airbrake
  +correctly, you can throw an error inside any of your routes:
  +```js
  +app.get('/hello/:name', function hello(req, res) {
  + throw new Error('hello from Express');
  + res.send(`Hello ${req.params.name}`);
  +});
  +```
  +
  +Any unhandled errors that are thrown will now be reported to Airbrake. See the
  +[basic usage](https://github.com/airbrake/airbrake-js/tree/master/packages/node#basic-usage)
  +to learn how to manually send errors to Airbrake.
  +
  +
  +**Note:** to see this all in action, take a look at our
  +[example `app.js` file](https://github.com/airbrake/airbrake-js/blob/master/packages/node/examples/express/app.js)
  +and to run the example, follow the next steps.
  +
  +
  +# Running the example app
  +
  +If you want to run this example application locally, follow these steps:
  +
  +#### 1. Clone the airbrake-js repo:
  +```shell
  +git clone git@github.com:airbrake/airbrake-js.git
  +```
  +#### 2. Navigate to this directory:
  +```
  +cd airbrake-js/packages/node/examples/express
  +```
  +#### 3. Run the following commands while providing your `project ID` and `project API key`
  +```shell
  +npm install
  +AIRBRAKE_PROJECT_ID=your-id AIRBRAKE_PROJECT_KEY=your-key node app.js
  firefox localhost:3000
  +```
  