Add more info on how to obtain an auth token.

Add example token command, details about auth token, and a
link to Github screen to revoke the token.

Author: timshadel

README.md

@@ -13,6 +13,7 @@ avoid setting the `GITHUB_AUTH_TOKEN` environment variable on your test & prod a
 and instead only set it on the app where you push your code & which runs the buildpack.
 
 [github-builds]: https://github.com/blog/1270-easier-builds-and-deployments-using-git-over-https-and-oauth
+[github-oauth]: http://developer.github.com/v3/oauth/#create-a-new-authorization
 
 Requirements
 ------------
@@ -23,22 +24,62 @@ The app must have `user-env-compile` enabled for the buildpack to have access to
 
 [Read more aobut user-env-compile.](https://devcenter.heroku.com/articles/labs-user-env-compile)
 
+You'll also need to make a Github authorization token. Here's the `curl` command you can use.
+
+```console
+$ curl -u 'my-read-only-user' -d '{"scopes":["repo"],"note":"GITHUB_AUTH_TOKEN for Heroku deplyoments","note_url":"https://github.com/timshadel/heroku-buildpack-github-netrc"}' https://api.github.com/authorizations  # Github API call
+Enter host password for user 'username':  [type password]
+
+{
+  "scopes": [
+    "repo"
+  ],
+  "token": "your_token",
+  "app": {
+    "url": "http://developer.github.com/v3/oauth/#oauth-authorizations-api",
+    "name": "Help example (API)"
+  },
+  "url": "https://api.github.com/authorizations/123456",
+  "note": "GITHUB_AUTH_TOKEN for Heroku deplyoments.",
+  "note_url": "https://github.com/timshadel/heroku-buildpack-github-netrc",
+  "id": 123456,
+}
+```
+
+This token may be revoked at any time by visiting the [Applications area][github-apps]
+of your Github account. You'll see the `note` linked to the `note_url` and the revoke
+button right next to it.
+
+Check out the [Github help article][github-oauth-help] and [OAuth documentation][github-oauth] for more details.
+
+[github-apps]: https://github.com/settings/applications
+[github-oauth-help]: https://help.github.com/articles/creating-an-oauth-token-for-command-line-use
+
 Usage
 -----
 
 Example usage:
 
     $ heroku create --stack cedar --buildpack http://github.com/fs-webdev/heroku-buildpack-netrc.git
 
-    # Enable 
+Enable config vars to be visible during buildpack execution, and set the token.
+
     $ heroku labs:enable user-env-compile
     $ heroku config:set GITHUB_AUTH_TOKEN=<my-read-only-token>
 
-    $ git push heroku master
-    ...
-    -----> Heroku receiving push
-    -----> Fetching custom buildpack
-    -----> Github .netrc app detected
-           Generated .netrc & .curlrc files (available only at build-time)
+Deploy your app.
+
+```console
+$ git push heroku master  # push your changes to Heroku
+
+...git output...
 
-TODO!
+-----> Fetching custom git buildpack... done
+-----> Multipack app detected
+=====> Downloading Buildpack: https://github.com/timshadel/heroku-buildpack-github-netrc.git
+=====> Detected Framework: github-netrc
+       Generated .netrc & .curlrc files (available only at build-time)
+       Github User:   my-read-only-user
+       Authorization: GITHUB_AUTH_TOKEN for Heroku deplyoments (private repo access)
+       Organizations: my-org, another-org
+```