Add carter.thedev.id (#490)

subdomains.json

@@ -36,6 +36,7 @@
   "breadomaticc": "breadomaticc.github.io",
   "bubbo": "bubbobtw.github.io",
   "calvin": "acongg2.github.io",
+  "carter": "cartercole.github.io",
   "connor": "connordoesdev.github.io",
   "cozmo": "cozmodev.github.io",
   "cozymy": "cozymy.github.io",