docs: update .all-contributorsrc [skip ci]

Author: allcontributors[bot]

.all-contributorsrc

@@ -6474,6 +6474,19 @@
         "doc",
         "code"
       ]
+    },
+    {
+      "login": "xinemata",
+      "name": "Xin Xin",
+      "avatar_url": "https://avatars.githubusercontent.com/u/9159424?v=4",
+      "profile": "https://github.com/xinemata",
+      "contributions": [
+        "eventOrganizing",
+        "tutorial",
+        "talk",
+        "mentoring",
+        "ideas"
+      ]
     }
   ],
   "repoType": "github",