Add Icelandic (#270)

Author: hph

langs/langs.json

@@ -11,6 +11,7 @@
   { "code": "hu", "name": "magyar", "enName": "Hungarian" },
   { "code": "id", "name": "Bahasa Indonesia", "enName": "Indonesian" },
   { "code": "it", "name": "Italiano", "enName": "Italian" },
+  { "code": "is", "name": "Íslenska", "enName": "Icelandic" },
   { "code": "ja", "name": "日本語", "enName": "Japanese" },
   { "code": "lo", "name": "ພາສາລາວ", "enName": "Lao" },
   { "code": "ko", "name": "한국어", "enName": "Korean" },