Add Isaac Sim introduction and ROS 2 integration guide (#179)

Add a new wiki entry providing an introduction to NVIDIA Isaac Sim, covering URDF import and ROS 2 integration.

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Co-authored-by: Nevin Valsaraj <nevin.valsaraj32@gmail.com>

Author: gauravsethia08

_data/navigation.yml

@@ -246,6 +246,8 @@ wiki:
         url: /wiki/simulation/Spawning-and-Controlling-Vehicles-in-CARLA
       - title: NDT Matching with Autoware
         url: /wiki/simulation/NDT-Matching-with-Autoware/
+      - title: An Introduction to Isaac Sim
+        url: /wiki/simulation/an-introduction-to-isaac-sim/
       - title: Simulating UGVs in Unity
         url: /wiki/simulation/simulating-ugvs-in-unity/
   - title: Interfacing