Updates mimic doc for manipulator success stats (#3833)

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Updates mimic doc for manipulator expected success stats for both
state-based and visuomotor policy training.
Enhances documentation for SkillGen & Imitation learning workflows. 

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- Documentation update


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Co-authored-by: Kelly Guo <[email protected]>

Author: michaellin6

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

@@ -315,6 +315,15 @@ By inferencing using the generated model, we can visualize the results of the po
          --device cpu --enable_cameras --task Isaac-Stack-Cube-Franka-IK-Rel-Visuomotor-v0 --num_rollouts 50 \
          --checkpoint /PATH/TO/desired_model_checkpoint.pth
 
+.. note::
+
+   **Expected Success Rates and Timings for Franka Cube Stack Task**
+
+   * Data generation success rate: ~50% (for both state + visuomotor)
+   * Data generation time: ~30 mins for state, ~4 hours for visuomotor (varies based on num envs the user runs)
+   * BC RNN training time: 1000 epochs + ~30 mins (for state), 600 epochs + ~6 hours (for visuomotor)
+   * BC RNN policy success rate: ~40-60% (for both state + visuomotor)
+
 
 Demo 1: Data Generation and Policy Training for a Humanoid Robot
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~