Update README.md

I just went through this process for the first time and noticed two opportunities to improve the docs here.

1. We tell customers to put the `new_relic_deploy.php` in the `private` directory, however, in the `pantheon.yml` config we call against the `/private/scripts` directory.
2. There are actually two places you want to change the User Key name if they don't use the default (terminus command, .php script), but the text could be interpreted as only being one (php script)

Author: dylanbaumann

new_relic_deploy/README.md

@@ -9,12 +9,12 @@ This example will show you how you can automatically log changes to your site in
 Setting up this example is easy:
 
 1. [Activate New Relic Pro](https://pantheon.io/docs/new-relic/#activate-new-relic-pro) within your site Dashboard.
-2. Get a [New Relic User Key](https://docs.newrelic.com/docs/apis/intro-apis/new-relic-api-keys/)
-3. Using [Terminus Secrets Manager Plugin](https://github.com/pantheon-systems/terminus-secrets-manager-plugin), set a site secret for the API key just created (e.g. `new_relic_api_key`, if you name it something else, make sure to update in the script below). Make sure type is `runtime` and scope contains `web`.
+2. Get a [New Relic User Key](https://one.newrelic.com/launcher/api-keys-ui.api-keys-launcher)
+3. Using [Terminus Secrets Manager Plugin](https://github.com/pantheon-systems/terminus-secrets-manager-plugin), set a site secret for the API key just created (e.g. `new_relic_api_key`, if you name it something else, make sure to update in the Terminus command below, and within the `new_relic_deploy.php` script in Step 4). Make sure type is `runtime` and scope contains `web`.
   ```
     terminus secret:site:set mysite new_relic_api_key --scope=web --type=runtime MY_API_KEY_HERE
   ```
-4. Add the example `new_relic_deploy.php` script to the `private` directory of your code repository.
+4. Add the example `new_relic_deploy.php` script to the `/private/scripts/` directory of your code repository.
 5. Add a Quicksilver operation to your `pantheon.yml` to fire the script after a deploy.
 6. Test a deploy out!