Adds section on isaac sim version in README (#2698)

# Description

Adds section in readme to highlight dependency of isaac sim versions for
different releases and branches of isaac lab.
Adds additional note about the Isaac Lab feature/isaacsim_5_0 branch
that currently requires the isaac sim OSS repo built from source.

## 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

<!--
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
-->

README.md

@@ -18,6 +18,7 @@
 
 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.
 
+
 ## Key Features
 
 Isaac Lab offers a comprehensive set of tools and environments designed to facilitate robot learning:
@@ -37,6 +38,27 @@ Our [documentation page](https://isaac-sim.github.io/IsaacLab) provides everythi
 - [Available environments](https://isaac-sim.github.io/IsaacLab/main/source/overview/environments.html)
 
 
+## Isaac Sim Version Dependency
+
+Isaac Lab is built on top of Isaac Sim and requires specific versions of Isaac Sim that are compatible with each release of Isaac Lab.
+Below, we outline the recent Isaac Lab releases and GitHub branches and their corresponding dependency versions for Isaac Sim.
+
+| Isaac Lab Version             | Isaac Sim Version |
+| ----------------------------- | ----------------- |
+| `main` branch                 | Isaac Sim 4.5     |
+| `v2.1.0`                      | Isaac Sim 4.5     |
+| `v2.0.2`                      | Isaac Sim 4.5     |
+| `v2.0.1`                      | Isaac Sim 4.5     |
+| `v2.0.0`                      | Isaac Sim 4.5     |
+| `feature/isaacsim_5_0` branch | Isaac Sim 5.0     |
+
+Note that the `feature/isaacsim_5_0` will contain active updates and may contain some breaking changes
+until the official Isaac Lab 2.2 release.
+It currently requires the [Isaac Sim 5.0 branch](https://github.com/isaac-sim/IsaacSim) available on GitHub built from source.
+Please refer to the README in the `feature/isaacsim_5_0` branch for instructions for using Isaac Lab with Isaac Sim 5.0.
+We are actively working on introducing backwards compatibility support for Isaac Sim 4.5 for this branch.
+
+
 ## Contributing to Isaac Lab
 
 We wholeheartedly welcome contributions from the community to make this framework mature and useful for everyone.