docs: update .all-contributorsrc

Author: allcontributors[bot]

.all-contributorsrc

@@ -261,6 +261,15 @@
         "example",
         "test"
       ]
+    },
+    {
+      "login": "amacati",
+      "name": "Martin Schuck",
+      "avatar_url": "https://avatars.githubusercontent.com/u/57562633?v=4",
+      "profile": "https://amacati.github.io/",
+      "contributions": [
+        "ideas"
+      ]
     }
   ]
 }