Updates Isaac Sim license (#3393)

# Description

Updates Isaac Sim license to the latest Apache 2.0 license and fixes
broken link in the docs.

## Type of change

- This change requires a documentation update

README.md

@@ -200,6 +200,8 @@ The Isaac Lab framework is released under [BSD-3 License](LICENSE). The `isaacla
 corresponding standalone scripts are released under [Apache 2.0](LICENSE-mimic). The license files of its
 dependencies and assets are present in the [`docs/licenses`](docs/licenses) directory.
 
+Note that Isaac Lab requires Isaac Sim, which includes components under proprietary licensing terms. Please see the [Isaac Sim license](docs/licenses/dependencies/isaacsim-license.txt) for information on Isaac Sim licensing.
+
 ## Acknowledgement
 
 Isaac Lab development initiated from the [Orbit](https://isaac-orbit.github.io/) framework. We would appreciate if

docs/source/refs/license.rst

@@ -3,15 +3,14 @@
 License
 ========
 
-NVIDIA Isaac Sim is available freely under `individual license
-<https://www.nvidia.com/en-us/omniverse/download/>`_. For more information
-about its license terms, please check `here <https://docs.omniverse.nvidia.com/app_isaacsim/common/NVIDIA_Omniverse_License_Agreement.html#software-support-supplement>`_.
+NVIDIA Isaac Sim is licensed under Apache 2.0. For more information
+about its license terms, please check `here <https://github.com/isaac-sim/IsaacLab/blob/main/docs/licenses/dependencies/isaacsim-license.txt>`_.
 The license files for all its dependencies and included assets are available in its
 `documentation <https://docs.isaacsim.omniverse.nvidia.com/latest/common/licenses.html>`_.
 
 
 The Isaac Lab framework is open-sourced under the
-`BSD-3-Clause license <https://opensource.org/licenses/BSD-3-Clause>`_.
+`BSD-3-Clause license <https://opensource.org/licenses/BSD-3-Clause>`_, with some dependencies licensed under other terms.
 
 
 .. code-block:: text