docs: add kewisch as a contributor for code (#647)

* docs: update README.md

* docs: update .all-contributorsrc

---------

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

.all-contributorsrc

@@ -163,6 +163,15 @@
       "contributions": [
         "bug"
       ]
+    },
+    {
+      "login": "kewisch",
+      "name": "Philipp Kewisch",
+      "avatar_url": "https://avatars.githubusercontent.com/u/607198?v=4",
+      "profile": "https://github.com/kewisch",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7,

README.md

@@ -1,6 +1,6 @@
 [<img src="https://f-droid.org/badge/get-it-on.png" alt="Get it on F-Droid" height="80">](https://f-droid.org/app/de.marmaro.krt.ffupdater)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-17-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-18-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # Firefox-Updater
@@ -107,6 +107,7 @@ For advanced users: [How to contribute](HOW_TO_CONTRIBUTE.md)
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/nortio"><img src="https://avatars.githubusercontent.com/u/22685799?v=4?s=100" width="100px;" alt="nortio"/><br /><sub><b>nortio</b></sub></a><br /><a href="https://github.com/Tobi823/ffupdater/commits?author=nortio" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/chenxiaolong"><img src="https://avatars.githubusercontent.com/u/646253?v=4?s=100" width="100px;" alt="Andrew Gunnerson"/><br /><sub><b>Andrew Gunnerson</b></sub></a><br /><a href="https://github.com/Tobi823/ffupdater/commits?author=chenxiaolong" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/TeeTeeHaa"><img src="https://avatars.githubusercontent.com/u/739754?v=4?s=100" width="100px;" alt="TeeTeeHaa"/><br /><sub><b>TeeTeeHaa</b></sub></a><br /><a href="https://github.com/Tobi823/ffupdater/issues?q=author%3ATeeTeeHaa" title="Bug reports">🐛</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/kewisch"><img src="https://avatars.githubusercontent.com/u/607198?v=4?s=100" width="100px;" alt="Philipp Kewisch"/><br /><sub><b>Philipp Kewisch</b></sub></a><br /><a href="https://github.com/Tobi823/ffupdater/commits?author=kewisch" title="Code">💻</a></td>
     </tr>
   </tbody>
   <tfoot>