Adding Versioning guidelines

Change-Id: I27307cea6a20ef385bff062b8dfdc2feb1fc6241
diff --git a/overview/releases.rst b/overview/releases.rst
index 8a0a9e4..42b30c3 100644
--- a/overview/releases.rst
+++ b/overview/releases.rst
@@ -93,5 +93,9 @@
      - July 11, 2021
      - December 30, 2022
      - Long Term Support Release
+   * - `VOLTHA 2.9 <../release_notes/voltha_2.9.rst>`_
+     - December 17, 2021
+     - June 30, 2022
+     -