Updates training_jetbot_reward_exploration.rst (#2788)

# Description

This is a small change to the Walkthrough documentation to make it
explicit to change the observation space dimension in the second half of
the Exploring the RL problem tutorial.

Fixes #2787

## Type of change

- This change is exclusively documentation

---------
Signed-off-by: Brian Bingham <briansbingham@gmail.com>
Signed-off-by: Michael Gussert <michael@gussert.com>
Co-authored-by: Michael Gussert <michael@gussert.com>

CONTRIBUTORS.md

@@ -46,6 +46,7 @@ Guidelines for modifications:
 * Bikram Pandit
 * Bingjie Tang
 * Brayden Zhang
+* Brian Bingham
 * Cameron Upright
 * Calvin Yu
 * Cheng-Rong Lai

docs/source/setup/walkthrough/training_jetbot_reward_exploration.rst

@@ -75,6 +75,8 @@ from linear algebra! Replace the contents of ``_get_observations`` with the foll
         observations = {"policy": obs}
         return observations
 
+We also need to **edit the ``IsaacLabTutorialEnvCfg`` to set the observation space back to 3** which includes the dot product, the z component of the cross product, and the forward speed.
+
 The dot or inner product tells us how aligned two vectors are as a single scalar quantity.  If they are very aligned and pointed in the same direction, then the inner
 product will be large and positive, but if they are aligned and in opposite directions, it will be large and negative.  If two vectors are
 perpendicular, the inner product is zero. This means that the inner product between the forward vector and the command vector can tell us