Update subdomains.json

subdomains.json

@@ -28,6 +28,7 @@
   "sazid": "palstheintrovert.github.io",
   "subtra3t": "subtra3t.github.io",
   "themoddedchicken": "themoddedchicken.github.io",
+  "thequackyduck": "thequackyduck.github.io",
   "wiktor": "wiktorwojcik112.github.io",
   "zh": "zh.github.io"  
 }