docs(@angular/cli): add github pages deploy docs (angular#6326)

Author: filipesilva

docs/documentation/stories.md

@@ -25,3 +25,4 @@
  - [Code Coverage](stories/code-coverage)
  - [Application Environments](stories/application-environments)
  - [Autoprefixer Configuration](stories/autoprefixer)
+ - [Deploy to GitHub Pages](stories/githug-pages)

docs/documentation/stories/github-pages.md

@@ -0,0 +1,21 @@
+# Deploy to GitHub Pages
+
+A simple way to deploy your Angular app is to use
+[GitHub Pages](https://help.github.com/articles/what-is-github-pages/).
+
+The first step is to [create a GitHub account](https://github.com/join), and then
+[create a repository](https://help.github.com/articles/create-a-repo/) for your project.
+Make a note of the user name and project name in GitHub.
+
+Then all you need to do is run `ng build --prod --output-path docs --base-href PROJECT_NAME`, where
+`PROJECT_NAME` is the name of your project in GitHub.
+Make a copy of `dist/index.html` and name it `dist/404.html`.
+
+Commit your changes and push. On the GitHub project page, configure it to
+[publish from the docs folder](https://help.github.com/articles/configuring-a-publishing-source-for-github-pages/#publishing-your-github-pages-site-from-a-docs-folder-on-your-master-branch).
+
+And that's all you need to do! Now you can see your page at
+`https://USER_NAME.github.io/PROJECT_NAME/`.
+
+You can also use [angular-cli-ghpages](https://github.com/angular-buch/angular-cli-ghpages), a full
+featured package that does this all this for you and has extra functionality.