Merge branch 'update-doc-links' into 'master'

Update README.md

This fixes some broken links in our documentation

See merge request !6857

docker/README.md

@@ -2,6 +2,6 @@
 
 * The official GitLab Community Edition Docker image is [available on Docker Hub](https://hub.docker.com/r/gitlab/gitlab-ce/).
 * The official GitLab Enterprise Edition Docker image is [available on Docker Hub](https://hub.docker.com/r/gitlab/gitlab-ee/).
-* The complete usage guide can be found in [Using GitLab Docker images](http://doc.gitlab.com/omnibus/docker/)
+* The complete usage guide can be found in [Using GitLab Docker images](https://docs.gitlab.com/omnibus/docker/)
 * The Dockerfile used for building public images is in [Omnibus Repository](https://gitlab.com/gitlab-org/omnibus-gitlab/tree/master/docker)
-* Check the guide for [creating Omnibus-based Docker Image](http://doc.gitlab.com/omnibus/build/README.html#build-docker-image)
+* Check the guide for [creating Omnibus-based Docker Image](https://docs.gitlab.com/omnibus/build/README.html#build-docker-image)