docs: add jwillebrands as a contributor (#216)

Author: allcontributors[bot]

.all-contributorsrc

@@ -216,6 +216,15 @@
       "contributions": [
         "infra"
       ]
+    },
+    {
+      "login": "jwillebrands",
+      "name": "Jan-Willem Willebrands",
+      "avatar_url": "https://avatars.githubusercontent.com/u/8925?v=4",
+      "profile": "https://github.com/jwillebrands",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -213,6 +213,7 @@ Thanks goes to these people ([emoji key][emojis]):
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/amitmiran137"><img src="https://avatars.githubusercontent.com/u/47772523?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Amit Miran</b></sub></a><br /><a href="#infra-amitmiran137" title="Infrastructure (Hosting, Build-Tools, etc)">🚇</a></td>
+    <td align="center"><a href="https://github.com/jwillebrands"><img src="https://avatars.githubusercontent.com/u/8925?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Jan-Willem Willebrands</b></sub></a><br /><a href="https://github.com/testing-library/angular-testing-library/commits?author=jwillebrands" title="Code">💻</a></td>
   </tr>
 </table>