[DOC] Broken link in appendix

[d-laing]

Problem
There is a broken link in Appendix D: Installing an OpenShift Cluster.

• appendix_deploying_openshift_cluster.adoc
• https://github.com/openshift/origin/blob/master/docs/cluster_up_down.md

Documentation Link
https://strimzi.io/docs/master/#installing_openshift_cluster

[wheresalice]

There's an OpenShift issue for this page going missing, and it turns out there are multiple ways of launching an OpenShift cluster now, so it's not as straightforward as just fixing a broken link.

[scholzj]

I think this section is not in our docs anymore.