docs: add @valentyntu as a contributor

.all-contributorsrc

@@ -3838,6 +3838,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "valentyntu",
+      "name": "Valentyn Tulub",
+      "avatar_url": "https://avatars.githubusercontent.com/u/40685314?v=4",
+      "profile": "https://github.com/valentyntu",
+      "contributions": [
+        "code"
+      ]
     }
   ]
 }

CONTRIBUTORS.md

@@ -549,6 +549,7 @@ 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/timwsuqld"><img src="https://avatars.githubusercontent.com/u/6201617?v=4?s=110" width="110px;" alt="Tim White"/><br /><sub><b>Tim White</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=timwsuqld" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/yannikp"><img src="https://avatars.githubusercontent.com/u/22473767?v=4?s=110" width="110px;" alt="yannikp"/><br /><sub><b>yannikp</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=yannikp" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/viclou"><img src="https://avatars.githubusercontent.com/u/20525448?v=4?s=110" width="110px;" alt="victoria"/><br /><sub><b>victoria</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=viclou" title="Code">💻</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/valentyntu"><img src="https://avatars.githubusercontent.com/u/40685314?v=4?s=110" width="110px;" alt="Valentyn Tulub"/><br /><sub><b>Valentyn Tulub</b></sub></a><br /><a href="https://github.com/snipe/snipe-it/commits?author=valentyntu" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>