Merge branch 'patch-3' into 'master'

adding link to .gitlab-ci.yml templates

closes #18998

## What does this MR do?

Add link to CI templates

## Are there points in the code the reviewer needs to double check?

No

## Why was this MR needed?

Asked by Sid - see #18998 

## What are the relevant issue numbers?

up 

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5033

doc/ci/examples/README.md

@@ -14,3 +14,4 @@
 - [Blog post about using GitLab CI for iOS projects](https://about.gitlab.com/2016/03/10/setting-up-gitlab-ci-for-ios-projects/)
 - [Repo's 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)
+- [A collection of useful .gitlab-ci.yml templates](https://gitlab.com/gitlab-org/gitlab-ci-yml)