integrate tsn and clean up

dist/test/assets/ts/index.d.ts

@@ -0,0 +1,4 @@
+declare let testplugin: {
+    logSomething: () => void;
+};
+export = testplugin;

dist/test/assets/ts/index.js

@@ -0,0 +1,7 @@
+"use strict";
+var testplugin = {
+    logSomething: function () {
+        console.log("only function executed");
+    }
+};
+module.exports = testplugin;