Update index.md

Author: chishengshih

docs/reference-design/index.md

@@ -7,7 +7,7 @@ The get started page provides the decision trees to find the reference design gu
 Below are the lists of the design guidelines. 
 
 
-## Main documentation links
+## Main documentation
 
 <div class="grid cards" markdown>
 
@@ -27,6 +27,19 @@ Below are the lists of the design guidelines.
 
   [:octicons-arrow-right-24: Link to the docs](https://autowarefoundation.github.io/LSA-reference-design-docs/main/)
 
+- **Off-Road Autonomy** Reference Design Documentation
+
+  ***
+  (Up coming in Q1/Q2 2026)
+
+  [:octicons-arrow-right-24: Link to the docs]()
+
+</div>
+
+## Racing Robots
+
+<div class="grid cards" markdown>
+ 
 - **RoboRacer** Reference Design Documentation
 
   ***
@@ -46,8 +59,6 @@ Below are the lists of the design guidelines.
 
 </div>
 
-</div>
-
 ### Buses 🚌
 - [ITRI Bus](itri-bus/index.md)