Fixes walkthrough path to in text for jetbot env (#2770)

Fixes link to python script in walkthrough tutorial

Fixes #2740 

## 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
- [X] I have added tests that prove my fix is effective or that my
feature works
- [X] 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

docs/source/setup/walkthrough/api_env_design.rst

@@ -78,7 +78,7 @@ the prim path with ``/World/envs/env_.*/Robot`` we are implicitly saying that ev
 The Environment
 -----------------
 
-Next, let's take a look at the contents of the other python file in our task directory: ``isaac_lab_tutorial_env_cfg.py``
+Next, let's take a look at the contents of the other python file in our task directory: ``isaac_lab_tutorial_env.py``
 
 .. code-block:: python