Updates readme for 2.2 (#568)

# Description

Updates README with 2.2 version compatibility and removes mentions of
the feature isaacsim5.0 branch since that will be replaced by the
official 2.2 release.

## 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

@@ -144,19 +144,15 @@ Isaac Lab is built on top of Isaac Sim and requires specific versions of Isaac S
 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     |
+| ----------------------------- | ------------------- |
+| `main` branch                 | Isaac Sim 5.0       |
+| `v2.2.0`                      | Isaac Sim 4.5 / 5.0 |
+| `v2.1.1`                      | 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.
+| `feature/isaacsim_5_0` branch | Isaac Sim 4.5 / 5.0 |
 
 
 ## Contributing to Isaac Lab