docs: add redeboer as a contributor for code (#589)

* 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

@@ -137,6 +137,15 @@
       "contributions": [
         "doc"
       ]
+    },
+    {
+      "login": "redeboer",
+      "name": "Remco de Boer",
+      "avatar_url": "https://avatars.githubusercontent.com/u/29308176?v=4",
+      "profile": "https://github.com/redeboer",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -458,6 +458,9 @@ We hereby acknowledge the contributors that made this project possible ([emoji k
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/amanmdesai"><img src="https://avatars.githubusercontent.com/u/98302868?v=4?s=100" width="100px;" alt="Aman Desai"/><br /><sub><b>Aman Desai</b></sub></a><br /><a href="https://github.com/scikit-hep/particle/commits?author=amanmdesai" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="http://jonathantellechea.com"><img src="https://avatars.githubusercontent.com/u/49012693?v=4?s=100" width="100px;" alt="Jonathan Tellechea"/><br /><sub><b>Jonathan Tellechea</b></sub></a><br /><a href="https://github.com/scikit-hep/particle/commits?author=JOTELLECHEA" title="Documentation">📖</a></td>
     </tr>
+    <tr>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/redeboer"><img src="https://avatars.githubusercontent.com/u/29308176?v=4?s=100" width="100px;" alt="Remco de Boer"/><br /><sub><b>Remco de Boer</b></sub></a><br /><a href="https://github.com/scikit-hep/particle/commits?author=redeboer" title="Code">💻</a></td>
+    </tr>
   </tbody>
 </table>