Simplification and comments for XML parser

src/layout_dom_node.rs

@@ -0,0 +1,12 @@
+// pub struct LayoutDomNode {
+// 	pub namespace: String,
+// 	pub name: String,
+// 	pub placement: 
+// 	// pub body: Vec<LayoutDomNode>
+// }
+
+// pub struct LayoutPlacement {
+// 	pub width: f32,
+// 	pub height: f32,
+// 	pub x_align: 
+// }