docs: update .all-contributorsrc [skip ci]

allcontributors[bot] · web-flow · commit 6480fcaf7c89 · 2020-09-22T08:39:00.000Z
diff --git a/.all-contributorsrc b/.all-contributorsrc
@@ -463,6 +463,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "lebedevsergey",
+      "name": "lebedevsergey",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/7325764?v=4",
+      "profile": "https://github.com/lebedevsergey",
+      "contributions": [
+        "doc"
+      ]
     }
   ],
   "contributorsPerLine": 8,
