Extend the language list as a test

Test if other languages can be quickly added to the engine.

lang.yaml

@@ -18,3 +18,8 @@ zh:
   language: "Chinese"
   locale: "zh_CN"
   google_dest: "zh-CN"
+pl:
+  index: 5
+  language: "Polish"
+  locale: "pl_PL"
+  google_dest: "pl"