Adds thumbnails of environments in benchmarking table (#109)

# Description
Adds thumbnails of environments in benchmarking table

docs/source/overview/reinforcement-learning/performance_benchmarks.rst

@@ -18,17 +18,30 @@ All benchmarking results were performed with the RL Games library with ``--headl
 Memory Consumption
 ^^^^^^^^^^^^^^^^^^
 
-+-------------------------------------+-------------------+----------+-----------+
-| Environment Name                    | # of Environments | RAM (GB) | VRAM (GB) |
-+=====================================+===================+==========+===========+
-| Isaac-Cartpole-Direct-v0            | 4096              | 3.7      | 3.3       |
-+-------------------------------------+-------------------+----------+-----------+
-| Isaac-Cartpole-RGB-Camera-Direct-v0 | 1024              | 7.5      | 16.7      |
-+-------------------------------------+-------------------+----------+-----------+
-| Isaac-Velocity-Rough-G1-v0          | 4096              | 6.5      | 6.1       |
-+-------------------------------------+-------------------+----------+-----------+
-| Isaac-Repose-Cube-Shadow-Direct-v0  | 8192              | 6.7      | 6.4       |
-+-------------------------------------+-------------------+----------+-----------+
++------------------------------------+----------------+-------------------+----------+-----------+
+| Environment Name                   |                | # of Environments | RAM (GB) | VRAM (GB) |
++====================================+================+===================+==========+===========+
+| Isaac-Cartpole-Direct-v0           | |cartpole|     | 4096              | 3.7      | 3.3       |
++------------------------------------+----------------+-------------------+----------+-----------+
+| Isaac-Cartpole-RGB-Camera-Direct-v0| |cartpole-cam| | 1024              | 7.5      | 16.7      |
++------------------------------------+----------------+-------------------+----------+-----------+
+| Isaac-Velocity-Rough-G1-v0         | |g1|           | 4096              | 6.5      | 6.1       |
++------------------------------------+----------------+-------------------+----------+-----------+
+| Isaac-Repose-Cube-Shadow-Direct-v0 | |shadow|       | 8192              | 6.7      | 6.4       |
++------------------------------------+----------------+-------------------+----------+-----------+
+
+.. |cartpole| image:: ../../_static/benchmarks/cartpole.jpg
+    :width: 80
+    :height: 45
+.. |cartpole-cam| image:: ../../_static/benchmarks/cartpole_camera.jpg
+    :width: 80
+    :height: 45
+.. |g1| image:: ../../_static/benchmarks/g1_rough.jpg
+    :width: 80
+    :height: 45
+.. |shadow| image:: ../../_static/benchmarks/shadow.jpg
+    :width: 80
+    :height: 45
 
 
 Single GPU - RTX 4090