Adds bin packing demo that showcasing RigidObjectCollection advanced use case (#3801)

# Description

This PR adds a demo that showcasing the advance usage of
RigidObjectCollection.
This shows spawning random number of objects and varying object types
per reset with a bin packing example.

## Type of change

- New feature (non-breaking change which adds functionality)

## Screenshots

![bin_packing](https://github.com/user-attachments/assets/196ff820-4973-45a5-8044-3057bbc60bfe)

## Checklist

- [x] I have read and understood the [contribution
guidelines](https://isaac-sim.github.io/IsaacLab/main/source/refs/contributing.html)
- [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
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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---------
Signed-off-by: ooctipus <zhengyuz@nvidia.com>
Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>

docs/source/overview/showroom.rst

@@ -193,6 +193,30 @@ A few quick showroom scripts to run and checkout:
       :alt: Multiple assets managed through the same simulation handles
 
 
+-  Use the RigidObjectCollection spawn and view manipulation to demonstrate bin-packing example:
+
+   .. tab-set::
+      :sync-group: os
+
+      .. tab-item:: :icon:`fa-brands fa-linux` Linux
+         :sync: linux
+
+         .. code:: bash
+
+            ./isaaclab.sh -p scripts/demos/bin_packing.py
+
+      .. tab-item:: :icon:`fa-brands fa-windows` Windows
+         :sync: windows
+
+         .. code:: batch
+
+            isaaclab.bat -p scripts\demos\bin_packing.py
+
+   .. image:: ../_static/demos/bin_packing.jpg
+      :width: 100%
+      :alt: Spawning random number of random asset per env_id using combination of MultiAssetSpawner and RigidObjectCollection
+
+
 
 -  Use the interactive scene and spawn a simple parallel robot for pick and place: