docs: add alexvanderberkel as a contributor for test (#604)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

---------

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>

Author: allcontributors[bot]

.all-contributorsrc

@@ -372,7 +372,8 @@
       "contributions": [
         "code",
         "ideas",
-        "review"
+        "review",
+        "test"
       ]
     }
   ],

README.md

@@ -757,7 +757,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     </tr>
     <tr>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/PepijnB"><img src="https://avatars.githubusercontent.com/u/24453103?v=4?s=100" width="100px;" alt="Pepijn Boer"/><br /><sub><b>Pepijn Boer</b></sub></a><br /><a href="https://github.com/AndreasAugustin/actions-template-sync/issues?q=author%3APepijnB" title="Bug reports">🐛</a></td>
-      <td align="center" valign="top" width="14.28%"><a href="https://github.com/alexvanderberkel"><img src="https://avatars.githubusercontent.com/u/862899?v=4?s=100" width="100px;" alt="Alex"/><br /><sub><b>Alex</b></sub></a><br /><a href="https://github.com/AndreasAugustin/actions-template-sync/commits?author=alexvanderberkel" title="Code">💻</a> <a href="#ideas-alexvanderberkel" title="Ideas, Planning, & Feedback">🤔</a> <a href="https://github.com/AndreasAugustin/actions-template-sync/pulls?q=is%3Apr+reviewed-by%3Aalexvanderberkel" title="Reviewed Pull Requests">👀</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/alexvanderberkel"><img src="https://avatars.githubusercontent.com/u/862899?v=4?s=100" width="100px;" alt="Alex"/><br /><sub><b>Alex</b></sub></a><br /><a href="https://github.com/AndreasAugustin/actions-template-sync/commits?author=alexvanderberkel" title="Code">💻</a> <a href="#ideas-alexvanderberkel" title="Ideas, Planning, & Feedback">🤔</a> <a href="https://github.com/AndreasAugustin/actions-template-sync/pulls?q=is%3Apr+reviewed-by%3Aalexvanderberkel" title="Reviewed Pull Requests">👀</a> <a href="https://github.com/AndreasAugustin/actions-template-sync/commits?author=alexvanderberkel" title="Tests">⚠️</a></td>
     </tr>
   </tbody>
 </table>