doc: add DreierF as contributor

Author: fabien0102

.all-contributorsrc

@@ -73,6 +73,15 @@
       "contributions": [
         "example"
       ]
+    },
+    {
+      "login": "DreierF",
+      "name": "Florian Dreier",
+      "avatar_url": "https://avatars.githubusercontent.com/u/5631865?v=4",
+      "profile": "https://github.com/DreierF",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7

README.md

@@ -170,6 +170,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/SferaDev"><img src="https://avatars.githubusercontent.com/u/2181866?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Alexis Rico</b></sub></a><br /><a href="https://github.com/fabien0102/openapi-codegen/commits?author=SferaDev" title="Code">💻</a> <a href="#ideas-SferaDev" title="Ideas, Planning, & Feedback">🤔</a></td>
     <td align="center"><a href="https://ned.im/"><img src="https://avatars.githubusercontent.com/u/271912?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Nedim Arabacı</b></sub></a><br /><a href="#question-needim" title="Answering Questions">💬</a> <a href="https://github.com/fabien0102/openapi-codegen/commits?author=needim" title="Code">💻</a> <a href="#ideas-needim" title="Ideas, Planning, & Feedback">🤔</a></td>
     <td align="center"><a href="https://github.com/antoniel"><img src="https://avatars.githubusercontent.com/u/17225358?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Antoniel Magalhães</b></sub></a><br /><a href="#example-antoniel" title="Examples">💡</a></td>
+    <td align="center"><a href="https://github.com/DreierF"><img src="https://avatars.githubusercontent.com/u/5631865?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Florian Dreier</b></sub></a><br /><a href="https://github.com/fabien0102/openapi-codegen/commits?author=DreierF" title="Code">💻</a></td>
   </tr>
 </table>