chore: add myself to contributors list

Author: RebeccaStevens

.all-contributorsrc

@@ -400,6 +400,13 @@
       "avatar_url": "https://avatars.githubusercontent.com/u/16860535?v=4",
       "profile": "https://github.com/soobing",
       "contributions": []
+    },
+    {
+      "login": "RebeccaStevens",
+      "name": "Rebecca Stevens",
+      "avatar_url": "https://avatars.githubusercontent.com/u/7224206?v=4",
+      "profile": "https://github.com/RebeccaStevens",
+      "contributions": []
     }
   ],
   "contributorsPerLine": 5