Merge branch 'patch-3' into 'master'

improve wording on build and push images using GitLab CI docs

## What does this MR do?

Improve wording on build and push images using GitLab CI docs

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

No

## Why was this MR needed?

Poor wording

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [X] [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)
- [X] 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 !6001

doc/container_registry/README.md

@@ -78,9 +78,9 @@ delete them.
 > **Note:**
 This feature requires GitLab 8.8 and GitLab Runner 1.2.
 
-Make sure that your GitLab Runner is configured to allow building docker images.
-You have to check the [Using Docker Build documentation](../ci/docker/using_docker_build.md).
-Then see the CI documentation on [Using the GitLab Container Registry](../ci/docker/using_docker_build.md#using-the-gitlab-container-registry).
+Make sure that your GitLab Runner is configured to allow building Docker images by
+following the [Using Docker Build](../ci/docker/using_docker_build.md)
+and [Using the GitLab Container Registry documentation](../ci/docker/using_docker_build.md#using-the-gitlab-container-registry).
 
 ## Limitations