feat: Replace new with start screen

- Convert to liquid
- Add old ongoing function for now
- Add macros as partials
- Rename data source to better reflect usage
- Update app.js to fulfill jshint

source/data/start.json

@@ -0,0 +1,14 @@
+[
+	{
+		"text": "Index",
+		"href": "/"
+	},
+	{
+		"text": "Basics",
+		"href": "/demo/basics.html"
+	},
+	{
+		"text": "Drag",
+		"href": "/demo/examples/ui/drag.html"
+	}
+]