[Add Language] Marko (#3519)

* add marko

* update marko

samples/Marko/rgb-sliders.marko

@@ -0,0 +1,36 @@
+static const colors = ['red', 'green', 'blue'];
+static const defaultColor = [255, 0, 0];
+
+class {
+	onInput(input) {
+		this.state = { color: input.color || defaultColor };
+	}
+
+	updateColor() {
+    	this.state.color = colors.map((color) => {
+        	return parseInt(this.getEl(color + 'Input').value, 10);
+        });
+    }
+
+    getStyleColor() {
+    	return 'rgb(' + this.state.color.join(',') + ')';
+    }
+}
+
+<div.rgb-sliders>
+    <div.inputs>
+    	<for(i, color in colors)>
+        	<div>
+                <label for-key=color+"Input">
+                    ${color}:
+                </label>
+                <input type="range" max="255"
+                    key=color+"Input"
+                    on-input('updateColor')
+                    value=state.color[i] >
+            </div>
+        </for>
+    </div>
+    <div.color style={backgroundColor: component.getStyleColor()}>
+    </div>
+</div>