docs: add mzdunek93 as a contributor (#575)

Author: allcontributors[bot]

.all-contributorsrc

@@ -917,6 +917,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "mzdunek93",
+      "name": "Michał Zdunek",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/10826511?v=4",
+      "profile": "https://github.com/mzdunek93",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "repoHost": "https://github.com"

README.md

@@ -251,6 +251,7 @@ Thanks goes to these people ([emoji key][emojis]):
   <tr>
     <td align="center"><a href="https://github.com/nstepien"><img src="https://avatars0.githubusercontent.com/u/567105?v=4" width="100px;" alt=""/><br /><sub><b>Nicolas Stepien</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=nstepien" title="Code">💻</a></td>
     <td align="center"><a href="https://knpw.rs"><img src="https://avatars0.githubusercontent.com/u/174864?v=4" width="100px;" alt=""/><br /><sub><b>Ken Powers</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=knpwrs" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/mzdunek93"><img src="https://avatars0.githubusercontent.com/u/10826511?v=4" width="100px;" alt=""/><br /><sub><b>Michał Zdunek</b></sub></a><br /><a href="https://github.com/testing-library/dom-testing-library/commits?author=mzdunek93" title="Code">💻</a></td>
   </tr>
 </table>