docs: add marscher as a contributor for code (#783)

* docs: update README.md [skip ci]

* docs: update .all-contributorsrc [skip ci]

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

.all-contributorsrc

@@ -376,6 +376,15 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "marscher",
+      "name": "Martin K. Scherer",
+      "avatar_url": "https://avatars.githubusercontent.com/u/170287?v=4",
+      "profile": "https://github.com/marscher",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -340,6 +340,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
       <td align="center"><a href="https://github.com/rgommers/"><img src="https://avatars.githubusercontent.com/u/98330?v=4?s=100" width="100px;" alt="Ralf Gommers"/><br /><sub><b>Ralf Gommers</b></sub></a><br /><a href="#ideas-rgommers" title="Ideas, Planning, & Feedback">🤔</a></td>
       <td align="center"><a href="https://github.com/tovrstra"><img src="https://avatars.githubusercontent.com/u/99431?v=4?s=100" width="100px;" alt="Toon Verstraelen"/><br /><sub><b>Toon Verstraelen</b></sub></a><br /><a href="https://github.com/nbQA-dev/nbQA/commits?author=tovrstra" title="Documentation">📖</a></td>
       <td align="center"><a href="https://github.com/tqa236"><img src="https://avatars.githubusercontent.com/u/25203655?v=4?s=100" width="100px;" alt="Trinh Quoc Anh"/><br /><sub><b>Trinh Quoc Anh</b></sub></a><br /><a href="https://github.com/nbQA-dev/nbQA/issues?q=author%3Atqa236" title="Bug reports">🐛</a></td>
+      <td align="center"><a href="https://github.com/marscher"><img src="https://avatars.githubusercontent.com/u/170287?v=4?s=100" width="100px;" alt="Martin K. Scherer"/><br /><sub><b>Martin K. Scherer</b></sub></a><br /><a href="https://github.com/nbQA-dev/nbQA/commits?author=marscher" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>