Add ironic-discoverd to Ironic project

This project is already a part of the Ironic community. There's no
reason to keep it on stackforge now, so let's move it to openstack/
and include it in the project's official listing.

Change-Id: Ie5ed5b11e841b52f9ea63b746d9be1eed5907a63

reference/projects.yaml

@@ -313,6 +313,9 @@ Ironic:
         - name: release:managed
         - name: release:at-6mo-cycle-end
         - name: release:has-stable-branches
+    - repo: openstack/ironic-discoverd
+      tags:
+        - name: release:independent
     - repo: openstack/ironic-lib
       tags:
         - name: release:independent