Simple Infinite Scrolling

While looking at the demo site of Twenty Fifteen (the theme I use for this blog), I noticed it used infinite scrolling, where more articles get automatically loaded when you reach the end of the page. It looked like a neat thing to have, but since I didn’t actually use WordPress, I couldn’t use the plugins that provide infinite scrolling. Writing it myself seemed like more effort than it was worth, so I dismissed it at the time.