[Add Language] Marko (#3519)

* add marko

* update marko

samples/Marko/counter.marko

@@ -0,0 +1,26 @@
+class {
+    constructor() {
+        this.state = { count:0 };
+    }
+    increment() {
+        this.state.count++;
+    }
+}
+
+style {
+    .count {
+        color:#09c;
+        font-size:3em;
+    }
+    .example-button {
+        font-size:1em;
+        padding:0.5em;
+    }
+}
+
+<div.count>
+    ${state.count}
+</div>
+<button.example-button on-click('increment')>
+    Click me!
+</button>