Updates dataset instruction in `teleop_imitation.rst` (#3462)

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Updates the Isaac Lab Mimic doc tutorials according to prior reviewer
feedback.
Changes:

1. Clarify demo success criteria for Demo 2 (humanoid pouring task)
2. Add visualization at the start of Demo 2 to clearly indicate that it
is a different task from Demo 1.
3. Document the dataset of Demo 2

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- Documentation update

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docs/source/overview/imitation-learning/teleop_imitation.rst

@@ -511,11 +511,17 @@ Visualize the results of the trained policy by running the following command, us
 Demo 2: Visuomotor Policy for a Humanoid Robot
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. figure:: https://download.isaacsim.omniverse.nvidia.com/isaaclab/images/gr-1_nut_pouring_policy.gif
+   :width: 100%
+   :align: center
+   :alt: GR-1 humanoid robot performing a pouring task
+   :figclass: align-center
+
 Download the Dataset
 ^^^^^^^^^^^^^^^^^^^^
 
-Download the pre-generated dataset from `here <https://download.isaacsim.omniverse.nvidia.com/isaaclab/dataset/generated_dataset_gr1_nut_pouring.hdf5>`__ and place it under ``IsaacLab/datasets/generated_dataset_gr1_nut_pouring.hdf5``.
-The dataset contains 1000 demonstrations of a humanoid robot performing a pouring/placing task that was
+Download the pre-generated dataset from `here <https://download.isaacsim.omniverse.nvidia.com/isaaclab/dataset/generated_dataset_gr1_nut_pouring.hdf5>`__ and place it under ``IsaacLab/datasets/generated_dataset_gr1_nut_pouring.hdf5``
+(**Note: The dataset size is approximately 12GB**). The dataset contains 1000 demonstrations of a humanoid robot performing a pouring/placing task that was
 generated using Isaac Lab Mimic for the ``Isaac-NutPour-GR1T2-Pink-IK-Abs-Mimic-v0`` task.
 
 .. hint::
@@ -526,7 +532,11 @@ generated using Isaac Lab Mimic for the ``Isaac-NutPour-GR1T2-Pink-IK-Abs-Mimic-
    Then, it drops the red beaker into the blue bin. Lastly, it places the yellow bowl onto the white scale.
    See the video in the :ref:`visualize-results-demo-2` section below for a visual demonstration of the task.
 
-   **Note that the following commands are only for your reference and are not required for this demo.**
+   **The success criteria for this task requires the red beaker to be placed in the blue bin, the green nut to be in the yellow bowl,
+   and the yellow bowl to be placed on top of the white scale.**
+
+   .. attention::
+      **The following commands are only for your reference and are not required for this demo.**
 
    To collect demonstrations: