Adds documentation for Isaac Sim OSS (#474)

# Description

Adds information and installation instructions for using Isaac Sim open
source repo.

## Type of change

- This change requires a documentation update

## 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

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README.md

@@ -14,6 +14,15 @@
 [![License](https://img.shields.io/badge/license-Apache--2.0-yellow.svg)](https://opensource.org/license/apache-2-0)
 
 
+This branch of Isaac Lab is a development branch compatible with the latest
+[Isaac Sim repository](https://github.com/isaac-sim/IsaacSim). Please note that some updates and changes are still being worked
+on until the official Isaac Lab 2.2 release. Currently, this branch requires the latest updates in the Isaac Sim open source repo.
+We are continuously working on enabling backwards compatibility with Isaac Sim 4.5, which is currently not possible with this branch.
+A quick list of updates and changes in this branch can be found in the [Release Notes](https://github.com/isaac-sim/IsaacLab/blob/feature/isaacsim_5_0/docs/source/refs/release_notes.rst).
+To run Isaac Lab with the Open Source Isaac Sim, please refer to
+[Getting Started with Open-Source Isaac Sim](#getting-started-with-open-source-isaac-sim).
+
+
 **Isaac Lab** is a GPU-accelerated, open-source framework designed to unify and simplify robotics research workflows, such as reinforcement learning, imitation learning, and motion planning. Built on [NVIDIA Isaac Sim](https://docs.isaacsim.omniverse.nvidia.com/latest/index.html), it combines fast and accurate physics and sensor simulation, making it an ideal choice for sim-to-real transfer in robotics.
 
 Isaac Lab provides developers with a range of essential features for accurate sensor simulation, such as RTX-based cameras, LIDAR, or contact sensors. The framework's GPU acceleration enables users to run complex simulations and computations faster, which is key for iterative processes like reinforcement learning and data-intensive tasks. Moreover, Isaac Lab can run locally or be distributed across the cloud, offering flexibility for large-scale deployments.
@@ -30,6 +39,83 @@ Isaac Lab offers a comprehensive set of tools and environments designed to facil
 
 ## Getting Started
 
+### Getting Started with Open-Source Isaac Sim
+
+Isaac Sim is now open source and available on GitHub! To run Isaac Lab with the open source Isaac Sim repo,
+ensure you are using the `feature/isaacsim_5_0` branch.
+
+For detailed Isaac Sim installation instructions, please refer to
+[Isaac Sim README](https://github.com/isaac-sim/IsaacSim?tab=readme-ov-file#quick-start).
+
+1. Clone Isaac Sim
+
+    ```
+    git clone https://github.com/isaac-sim/IsaacSim.git
+    ```
+
+2. Build Isaac Sim
+
+    ```
+    cd isaacsim
+    ./build.sh
+    ```
+
+    On Windows, please use `build.bat` instead.
+
+3. Clone Isaac Lab
+
+    ```
+    cd ..
+    git clone -b feature/isaacsim_5_0 https://github.com/isaac-sim/IsaacLab.git
+    cd isaaclab
+    ```
+
+4. Set up symlink in Isaac Lab
+
+    Linux:
+
+    ```
+    ln -s isaacsim/_build/linux-x86_64/release _isaac_sim
+    ```
+
+    Windows:
+
+    ```
+    mklink /D _isaac_sim isaacsim\_build\windows-x86_64\release
+    ```
+
+5. Install Isaac Lab
+
+    Linux:
+
+    ```
+    ./isaaclab.sh -i
+    ```
+
+    Windows:
+
+    ```
+    isaaclab.bat -i
+    ```
+
+6. Train!
+
+    Linux:
+
+    ```
+    ./isaaclab.sh -p scripts/reinforcement_learning/skrl/train.py --task Isaac-Ant-v0 --headless
+    ```
+
+    Windows:
+
+    ```
+    isaaclab.bat -p scripts\reinforcement_learning\skrl\train.py --task Isaac-Ant-v0 --headless
+    ```
+
+### Documentation
+
+Note that the current public documentations may not include all features of the latest feature/isaacsim_5_0 branch.
+
 Our [documentation page](https://isaac-sim.github.io/IsaacLab) provides everything you need to get started, including detailed tutorials and step-by-step guides. Follow these links to learn more about:
 
 - [Installation steps](https://isaac-sim.github.io/IsaacLab/main/source/setup/installation/index.html#local-installation)

docs/source/refs/release_notes.rst

@@ -7,15 +7,30 @@ We summarize the release notes here for convenience.
 v2.2.0
 ======
 
-Breaking Changes
-----------------
+Updates and Changes
+-------------------
 
+* Python version has been updated to 3.11 from 3.10.
+* PyTorch version is updated to torch 2.7.0+cu128, which will include Blackwell support.
+* Rendering issues have been resolved on Blackwell GPUs that previously resulted in overly noisy renders.
+* Official support for Ubuntu 20.04 has been dropped. We now officially support Ubuntu 22.04 and 24.04 Linux platforms.
+* Updated gymnasium to be at least v1.0.0 to allow for specifying module name with task name in the form of module:task.
+* New Spatial Tendon APIs are introduced to allow simulation and actuation of assets with spatial tendons.
 * :attr:`~isaaclab.sim.spawners.PhysicsMaterialCfg.improve_patch_friction` is now removed. The simulation will always behave as if this attribute is set to true.
 * Native Livestreaming support has been removed. ``LIVESTREAM=1`` can now be used for WebRTC streaming over public networks and
   ``LIVESTREAM=2`` for private and local networks with WebRTC streaming.
-* Python version has been updated to 3.11 from 3.10
-* Official support for Ubuntu 20.04 has been dropped. We now officially support Ubuntu 22.04 and 24.04 Linux platforms.
 * Isaac Sim 5.0 no longer sets ``/app/player/useFixedTimeStepping=False`` by default. We now do this in Isaac Lab.
+* We are leveraging the latest Fabric implementations to allow for faster scene creation and interop between the simulator and rendering. This should help improve rendering performance as well as startup time.
+* Some assets in Isaac Sim have been reworked and restructured. Notably, the following asset paths were updated:
+  * ``Robots/Ant/ant_instanceable.usd`` --> ``Robots/IsaacSim/Ant/ant_instanceable.usd``
+  * ``Robots/Humanoid/humanoid_instanceable.usd`` --> ``Robots/IsaacSim/Humanoid/humanoid_instanceable.usd``
+  * ``Robots/ANYbotics/anymal_instanceable.usd`` --> ``Robots/ANYbotics/anymal_c/anymal_c.usd``
+  * ``Robots/ANYbotics/anymal_c.usd`` --> ``Robots/ANYbotics/anymal_c/anymal_c.usd``
+  * ``Robots/Franka/franka.usd`` --> ``Robots/FrankaRobotics/FrankaPanda/franka.usd``
+  * ``Robots/AllegroHand/allegro_hand_instanceable.usd`` --> ``Robots/WonikRobotics/AllegroHand/allegro_hand_instanceable.usd``
+  * ``Robots/Crazyflie/cf2x.usd`` --> ``Robots/Bitcraze/Crazyflie/cf2x.usd``
+  * ``Robots/RethinkRobotics/sawyer_instanceable.usd`` --> ``Robots/RethinkRobotics/Sawyer/sawyer_instanceable.usd``
+  * ``Robots/ShadowHand/shadow_hand_instanceable.usd`` --> ``Robots/ShadowRobot/ShadowHand/shadow_hand_instanceable.usd``
 
 
 v2.1.0