Adds pre-recorded dataset link to Mimic docs (#232)

# Description

Update Isaac Lab Mimic docs with S3 link to pre-recorded human demo
dataset.

## Type of change

<!-- As you go through the list, delete the ones that are not
applicable. -->

- Documentation change

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [ ] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

<!--
As you go through the checklist above, you can mark something as done by
putting an x character in it

For example,
- [x] I have done this task
- [ ] I have not done this task
-->

---------
Signed-off-by: Kelly Guo <kellyguo123@hotmail.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>

docs/source/overview/teleop_imitation.rst

@@ -101,6 +101,14 @@ If, while performing a demonstration, a mistake is made, or the current demonstr
 .. note::
    Non-determinism may be observed during replay as physics in IsaacLab are not determimnistically reproducible when using ``env.reset``.
 
+Pre-recorded demonstrations
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+We provide a pre-recorded ``dataset.hdf5`` containing 10 human demonstrations for ``Isaac-Stack-Cube-Franka-IK-Rel-v0`` `here <https://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.5/Isaac/IsaacLab/Mimic/dataset.hdf5>`_.
+This dataset may be downloaded and used in the remaining tutorial steps if you do not wish to collect your own demonstrations.
+
+.. note::
+   Use of the pre-recorded dataset is optional.
 
 Generating additional demonstrations
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^