Add release notes for tempest release 11.0.0

This commit adds the release notes necessary prior to pushing the 11.0.0
release. It basically just indicates the supported versions in the tag.

Change-Id: I211b0557c28e78b286a1d6b204d42bda8b10bbd6
diff --git a/releasenotes/notes/11.0.0-supported-openstack-releases-1e5d7295d939d439.yaml b/releasenotes/notes/11.0.0-supported-openstack-releases-1e5d7295d939d439.yaml
new file mode 100644
index 0000000..09ff15d
--- /dev/null
+++ b/releasenotes/notes/11.0.0-supported-openstack-releases-1e5d7295d939d439.yaml
@@ -0,0 +1,12 @@
+---
+prelude: >
+    This release is marking the start of Mitaka release support in tempest
+other:
+    - OpenStack Releases Supported at this time are **Kilo**, **Liberty**,
+      **Mitaka**
+
+      The release under current development as of this tag is Newton,
+      meaning that every Tempest commit is also tested against master during
+      the Newton cycle. However, this does not necessarily mean that using
+      Tempest as of this tag will work against a Newton (or future releases)
+      cloud.