Need to document Custom Notification

[dtaylor113]

Hi,
Need to document how to setup custom quota notification messages:

window.OPENSHIFT_CONSTANTS.QUOTA_NOTIFICATION_MESSAGE = {
  // Example quota messages to show in notification drawer
  // "pods": "Upgrade to <a href='http://www.openshift.com'>OpenShift Pro</a> if you need additional resources.",
  // "limits.memory": "Upgrade to <a href='http://www.openshift.com'>OpenShift Online Pro</a> if you need additional resources."
}

https://github.com/openshift/openshift-docs/blob/master/install_config/web_console_customization.adoc

Related PR: openshift/origin-web-console#2116

[dtaylor113]

I believe this was implemented with #5310