Fixes incorrect local documentation preview path in xdg-open command (#1776)

# Description

This PR fixes the `xdg-open` command in the documentation that instructs
users on how to preview the documentation locally. Previously, the
command pointed to `docs/_build/html/index.html`, which is incorrect.
The correct path is now `docs/_build/current/index.html`.

## Type of change

- Bug fix (non-breaking change which fixes an issue)
- 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
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

docs/source/refs/contributing.rst

@@ -151,7 +151,7 @@ in the terminal:
 
 .. code:: bash
 
-   xdg-open docs/_build/html/index.html
+   xdg-open docs/_build/current/index.html
 
 .. hint::
 

source/isaaclab/docs/CHANGELOG.rst

@@ -64,7 +64,7 @@ Fixed
 Fixed
 ^^^^^
 
-]* Removed deprecation of :attr:`isaaclab.assets.ArticulationData.root_state_w` and
+* Removed deprecation of :attr:`isaaclab.assets.ArticulationData.root_state_w` and
   :attr:`isaaclab.assets.ArticulationData.body_state_w` derived properties.
 * Removed deprecation of :meth:`isaaclab.assets.Articulation.write_root_state_to_sim`.
 * Replaced calls to :attr:`isaaclab.assets.ArticulationData.root_com_state_w` and