Add some content

Signed-off-by: RMidhunSuresh <rmidhunsuresh@gmail.com>

documentation/UI/index.md

@@ -0,0 +1,3 @@
+# Index for UI code
+
+1. [Rendering DOM elements](./render-dom-elements.md)

documentation/UI/render-dom-elements.md

@@ -0,0 +1,18 @@
+There are two options to render DOM elements:
+- Use `tag` from `ui/general/html.js`
+- Use `TemplateBuilder` object (t) from the render function in the view.
+
+Although syntactically similar, they are not functionally equivalent.  
+Primarily `tag` **does not support** bindings nor event handlers.
+
+```js
+    // The onClick here wont work!!
+    tag.button({className:"awesome-btn", onClick: () => this.foo()});
+```
+ For these functionalities always use the TemplateBuilder object that is passed as argument to the render method.
+```js
+    render(t, vm){
+        // The onClick works here.
+        t.button({className:"awesome-btn", onClick: () => this.foo()});
+    }
+```