docs: add @mbrrg as a contributor

.all-contributorsrc

@@ -3595,6 +3595,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "mbrrg",
+      "name": "Martin Berg",
+      "avatar_url": "https://avatars.githubusercontent.com/u/2682426?v=4",
+      "profile": "https://github.com/mbrrg",
+      "contributions": [
+        "code"
+      ]
     }
   ]
 }

CONTRIBUTORS.md

@@ -514,6 +514,7 @@ Thanks goes to all of these wonderful people ([emoji key](https://github.com/ken
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/manu-crealytics"><img src="https://avatars.githubusercontent.com/u/18286893?v=4?s=110" width="110px;" alt="manu-crealytics"/><br /><sub><b>manu-crealytics</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=manu-crealytics" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://www.galaxy102.de/"><img src="https://avatars.githubusercontent.com/u/18245993?v=4?s=110" width="110px;" alt="Konstantin Köhring"/><br /><sub><b>Konstantin Köhring</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=Galaxy102" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://deloz.net/"><img src="https://avatars.githubusercontent.com/u/685167?v=4?s=110" width="110px;" alt="Deloz"/><br /><sub><b>Deloz</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=deloz" title="Code">💻</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/mbrrg"><img src="https://avatars.githubusercontent.com/u/2682426?v=4?s=110" width="110px;" alt="Martin Berg"/><br /><sub><b>Martin Berg</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=mbrrg" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>