docs: add MattijsE as a contributor for code (#567)

* 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

@@ -475,6 +475,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "MattijsE",
+      "name": "MattijsE",
+      "avatar_url": "https://avatars.githubusercontent.com/u/9746064?v=4",
+      "profile": "https://github.com/MattijsE",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -282,6 +282,9 @@ Thanks goes to these people ([emoji key][emojis]):
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/jdegand"><img src="https://avatars.githubusercontent.com/u/70610011?v=4?s=100" width="100px;" alt="J. Degand"/><br /><sub><b>J. Degand</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=jdegand" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/artaommahe"><img src="https://avatars.githubusercontent.com/u/1944061?v=4?s=100" width="100px;" alt="Maksim Popov"/><br /><sub><b>Maksim Popov</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=artaommahe" title="Code">💻</a></td>
     </tr>
+    <tr>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/MattijsE"><img src="https://avatars.githubusercontent.com/u/9746064?v=4?s=100" width="100px;" alt="MattijsE"/><br /><sub><b>MattijsE</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=MattijsE" title="Code">💻</a></td>
+    </tr>
   </tbody>
 </table>