[Newton] Updates newton visualizer documentation (isaac-sim#3551)

# Description

Updates documentation for Newton visualizer in preparation for the corl
release of Newton.

Fixes # (issue)

<!-- As a practice, it is recommended to open an issue to have
discussions on the proposed pull request.
This makes it easier for the community to keep track of what is being
developed or added, and if a given feature
is demanded by more than one party. -->

## Type of change

- Documentation update

## Screenshots

Please attach before and after screenshots of the change if applicable.

<!--
Example:

| Before | After |
| ------ | ----- |
| _gif/png before_ | _gif/png after_ |

To upload images to a PR -- simply drag and drop an image while in edit
mode and it should upload the image directly. You can then paste that
source into the above before/after sections.
-->

## Checklist

- [ ] I have read and understood the [contribution
guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
- [ ] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [ ] 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
-->

Co-authored-by: Milad-Rakhsha <miladrakhsha@gmail.com>

Author: Milad-Rakhsha-NV

docs/source/experimental-features/newton-physics-integration/newton-visualizer.rst

@@ -32,4 +32,8 @@ lower number of environments, we can omit the ``--headless`` option while still
 
 These options are available across all the learning frameworks.
 
-For more information about the Newton Visualizer, please refer to the `Newton documentation <https://newton-physics.github.io/newton/guide/visualization.html>`_ .
+For more information about the Newton Visualizer, please refer to the `Newton documentation <https://newton-physics.github.io/newton/guide/visualization.html>`_.
+
+IsaacLab provides additional customizations to the Newton visualizer with several learning-oriented features. These include the ability to pause rendering during training or pause the training process itself. Pausing rendering accelerates training by skipping rendering frames, which is particularly useful when we want to periodically check the trained policy without the performance overhead of continuous rendering. Pausing the training process is valuable for debugging purposes. Additionally, the visualizer's update frequency can be adjusted using a slider in the visualizer window, making it easy to prioritize rendering quality against training performance and vice-versa.
+
+All IsaacLab-specific customizations are organized under the *IsaacLab Training Controls* tab in the visualizer window.