Refactor CI index page

doc/ci/README.md

-# GitLab CI Documentation
-## CI User documentation
+# GitLab Continuous Integration
+![CI/CD pipeline graph](img/cicd_pipeline_infograph.png)
+
+The benefits of Continuous Integration are huge when automation plays an
+integral part of your workflow. GitLab comes with integrated Continuous
+Integration (CI) and Continuous Delivery (CD) to test, build and deploy your
+code.
+
+Here's some info we've gathered to get you started.
+
+## Getting started
 - [Getting started with GitLab CI](quick_start/README.md)
-- [CI examples for various languages](examples/README.md)
-- [Learn how to enable or disable GitLab CI](enable_or_disable_ci.md)
+- [Configure a Runner, the application that runs your jobs](runners/README.md)
 - [Pipelines and jobs](pipelines.md)
 - [Environments and deployments](environments.md)
-- [Learn how `.gitlab-ci.yml` works](yaml/README.md)
-- [Configure a Runner, the application that runs your jobs](runners/README.md)
-- [Use Docker images with GitLab Runner](docker/using_docker_images.md)
-- [Use CI to build Docker images](docker/using_docker_build.md)
+- [Job artifacts](../user/project/pipelines/job_artifacts.md)
+- **Using Docker**
+  - [Use Docker images with GitLab Runner](docker/using_docker_images.md)
+  - [Use CI to build Docker images](docker/using_docker_build.md)
+  - [CI services (linked Docker containers)](services/README.md)
+- **Blog posts**
+  - [Getting started with GitLab and GitLab CI](https://about.gitlab.com/2015/12/14/getting-started-with-gitlab-and-gitlab-ci/)
+  - [GitLab CI: Run jobs sequentially, in parallel or build a custom pipeline](https://about.gitlab.com/2016/07/29/the-basics-of-gitlab-ci/)
+  - [Continuous Integration, Delivery, and Deployment with GitLab](https://about.gitlab.com/2016/08/05/continuous-integration-delivery-and-deployment-with-gitlab/)
+  - [CI deployments and environments](https://about.gitlab.com/2016/08/26/ci-deployment-and-environments/)
+- **Videos**
+  - [Getting started with CI in GitLab](https://about.gitlab.com/2016/04/20/webcast-recording-and-slides-introduction-to-ci-in-gitlab/)
+
+## Reference guides
+
+Once you get familiar with the getting started guides, you'll find yourself
+digging into specific reference guides.
+
+- [`.gitlab-ci.yml` reference](yaml/README.md)
+- **The permissions model**
+  - [User permissions](../user/permissions.md#gitlab-ci)
+  - [Jobs permissions](../user/permissions.md#jobs-permissions)
 - [CI Variables](variables/README.md) - Learn how to use variables defined in
   your `.gitlab-ci.yml` or secured ones defined in your project's settings
-- [Use SSH keys in your build environment](ssh_keys/README.md)
-- [Trigger jobs through the API](triggers/README.md)
-- [Job artifacts](../user/project/pipelines/job_artifacts.md)
-- [User permissions](../user/permissions.md#gitlab-ci)
-- [Jobs permissions](../user/permissions.md#jobs-permissions)
-- [API](../api/ci/README.md)
-- [CI services (linked docker containers)](services/README.md)
-- [CI/CD pipelines settings](../user/project/pipelines/settings.md)
+
+## Advanced use
+
+- [Git submodules](git_submodules.md)
 - [Review Apps](review_apps/index.md)
-- [Git submodules](git_submodules.md) Using Git submodules in your CI jobs
 - [Auto deploy](autodeploy/index.md)
+- [Use SSH keys in your build environment](ssh_keys/README.md)
+- [Trigger jobs through the GitLab API](triggers/README.md)
+- [Using GitLab CI with GitLab Pages](../user/project/pages/index.md)
+
+## Special project configuration
+
+- [CI/CD pipelines settings](../user/project/pipelines/settings.md)
+- [Learn how to enable or disable GitLab CI](enable_or_disable_ci.md)
+
+## Examples
+
+>**Note:**
+A collection of `.gitlab-ci.yml` files is maintained at the
+[GitLab CI Yml project][gitlab-ci-templates].
+If your favorite programming language or framework are missing we would love
+your help by sending a merge request with a `.gitlab-ci.yml`.
+
+Here is an collection of tutorials and guides on setting up your CI pipeline:
+
+- **Languages and frameworks**
+  - [Testing a PHP application](examples/php.md)
+  - [Test and deploy a Ruby application to Heroku](examples/test-and-deploy-ruby-application-to-heroku.md)
+  - [Test and deploy a Python application to Heroku](examples/test-and-deploy-python-application-to-heroku.md)
+  - [Test a Clojure application](examples/test-clojure-application.md)
+  - [Test a Scala application](examples/test-scala-application.md)
+  - [Test a Phoenix application](examples/test-phoenix-application.md)
+  - [Run PHP Composer & NPM scripts then deploy them to a staging server](examples/deployment/composer-npm-deploy.md)
+- **Blog posts**
+  - [Automated Debian packaging](https://about.gitlab.com/2016/10/12/automated-debian-package-build-with-gitlab-ci/)
+  - [Spring boot application with GitLab CI and Kubernetes](https://about.gitlab.com/2016/11/30/setting-up-gitlab-ci-for-android-projects/)
+  - [Setting up CI for iOS projects](https://about.gitlab.com/2016/12/14/continuous-delivery-of-a-spring-boot-application-with-gitlab-ci-and-kubernetes/)
+  - [Using GitLab CI for iOS projects](https://about.gitlab.com/2016/03/10/setting-up-gitlab-ci-for-ios-projects/)
+  - [Setting up GitLab CI for Android projects](https://about.gitlab.com/2016/11/30/setting-up-gitlab-ci-for-android-projects/)
+  - [Building a new GitLab Docs site with Nanoc, GitLab CI, and GitLab Pages](https://about.gitlab.com/2016/12/07/building-a-new-gitlab-docs-site-with-nanoc-gitlab-ci-and-gitlab-pages/)
+  - [CI/CD with GitLab in action](https://about.gitlab.com/2017/03/13/ci-cd-demo/)
+  - [Building an Elixir Release into a Docker image using GitLab CI](https://about.gitlab.com/2016/08/11/building-an-elixir-release-into-docker-image-using-gitlab-ci-part-1/)
+- **Miscellaneous**
+  - [Using `dpl` as deployment tool](examples/deployment/README.md)
+  - [Repositories with examples for various languages](https://gitlab.com/groups/gitlab-examples)
+  - [The .gitlab-ci.yml file for GitLab itself](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/.gitlab-ci.yml)
+  - [Example project that shows how to use Review Apps](https://gitlab.com/gitlab-examples/review-apps-nginx/)
 ## Breaking changes
-- [CI variables renaming](variables/README.md#9-0-renaming) Read about the
+- [CI variables renaming for GitLab 9.0](variables/README.md#9-0-renaming) Read about the
   deprecated CI variables and what you should use for GitLab 9.0+.
 - [New CI job permissions model](../user/project/new_ci_build_permissions_model.md)
   Read about what changed in GitLab 8.12 and how that affects your jobs.
   There's a new way to access your Git submodules and LFS objects in jobs.
+
+[gitlab-ci-templates]: https://gitlab.com/gitlab-org/gitlab-ci-yml