doc: add 1.3.0 to documentation list

Change-Id: I496b48fffda100bf577680e2abad3b030746e0b5
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/doc/index.rst b/doc/index.rst
index cd17695..95c7731 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -17,10 +17,10 @@
    master tree under development.
 
    Documentation for released versions of Zephyr can be found at
-   ``https://www.zephyrproject.org/doc/<version>``, for example:
+   ``https://www.zephyrproject.org/doc/<version>``. The following documentation
+   versions are vailable:
 
-   * Documentation for `Zephyr 1.2.0`_
-   * Documentation for `Zephyr 1.1.0`_
+   `Zephyr 1.1.0`_ | `Zephyr 1.2.0`_ | `Zephyr 1.3.0`_
 
 Sections
 ********
@@ -51,5 +51,6 @@
 * :ref:`search`
 
 .. _Zephyr Project Wiki: https://wiki.zephyrproject.org/view/Main_Page
+.. _Zephyr 1.3.0: https://www.zephyrproject.org/doc/1.3.0/
 .. _Zephyr 1.2.0: https://www.zephyrproject.org/doc/1.2.0/
 .. _Zephyr 1.1.0: https://www.zephyrproject.org/doc/1.1.0/