docs: add fergusmcdonald as a contributor (#612)

* docs: update README.md

* docs: update .all-contributorsrc

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

.all-contributorsrc

@@ -808,6 +808,15 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "fergusmcdonald",
+      "name": "Fergus McDonald",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3115675?v=4",
+      "profile": "https://fergusmcdonald.com",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "commitConvention": "none",

README.md

@@ -766,6 +766,7 @@ Thanks goes to these people ([emoji key][emojis]):
     <td align="center"><a href="https://github.com/mkapal"><img src="https://avatars.githubusercontent.com/u/6420535?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Martin Kapal</b></sub></a><br /><a href="https://github.com/testing-library/user-event/issues?q=author%3Amkapal" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://gr.linkedin.com/in/bastakis"><img src="https://avatars.githubusercontent.com/u/1146626?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Stavros</b></sub></a><br /><a href="https://github.com/testing-library/user-event/issues?q=author%3Asstauross" title="Bug reports">🐛</a></td>
     <td align="center"><a href="https://github.com/geoffroymounier"><img src="https://avatars.githubusercontent.com/u/24386870?v=4?s=100" width="100px;" alt=""/><br /><sub><b>geoffroymounier</b></sub></a><br /><a href="https://github.com/testing-library/user-event/issues?q=author%3Ageoffroymounier" title="Bug reports">🐛</a></td>
+    <td align="center"><a href="https://fergusmcdonald.com"><img src="https://avatars.githubusercontent.com/u/3115675?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Fergus McDonald</b></sub></a><br /><a href="https://github.com/testing-library/user-event/commits?author=fergusmcdonald" title="Code">💻</a></td>
   </tr>
 </table>