docs: add the-ult as a contributor (#200)

Author: allcontributors[bot]

.all-contributorsrc

@@ -188,6 +188,15 @@
         "code",
         "test"
       ]
+    },
+    {
+      "login": "the-ult",
+      "name": "Arjen",
+      "avatar_url": "https://avatars.githubusercontent.com/u/4863062?v=4",
+      "profile": "https://github.com/the-ult",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -208,6 +208,7 @@ Thanks goes to these people ([emoji key][emojis]):
     <td align="center"><a href="http://wwww.reibo.be"><img src="https://avatars1.githubusercontent.com/u/1673799?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Bo Vandersteene</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=bovandersteene" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/jbchr"><img src="https://avatars1.githubusercontent.com/u/23141806?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Janek</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=jbchr" title="Code">💻</a> <a href="https://github.com/testing-library/angular-testing-library/commits?author=jbchr" title="Tests">⚠️</a></td>
     <td align="center"><a href="https://github.com/GlebIrovich"><img src="https://avatars.githubusercontent.com/u/33176414?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Gleb Irovich</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=GlebIrovich" title="Code">💻</a> <a href="https://github.com/testing-library/angular-testing-library/commits?author=GlebIrovich" title="Tests">⚠️</a></td>
+    <td align="center"><a href="https://github.com/the-ult"><img src="https://avatars.githubusercontent.com/u/4863062?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Arjen</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=the-ult" title="Code">💻</a></td>
   </tr>
 </table>