Add 3.4 to index

Author: lenkis

doc/release/index.rst

@@ -61,6 +61,12 @@ For information about earlier versions, see :doc:`eol_versions`.
             -   End of support
             -   Versions
 
+        *   -   :doc:`3.4 </release/3.4.0>`
+            -   **April 15, 2025**
+            -   **April 15, 2027**
+            -   **Not planned yet**
+            -   | :tarantool-release:`3.4.0`
+
         *   -   :doc:`3.3 </release/3.3.0>`
             -   **November 29, 2024**
             -   **November 29, 2026**