1.2 Static images
This page is 1.2. For a plain (non-interactive) picture — a diagram, a scan, a photo — drop the file next to the page and link to it with normal Markdown image syntax:
The text in the brackets is the description (shown if the image can’t load and
read by screen readers). The site automatically optimises raster images
(.png/.jpg) into web-friendly formats, so you can drop in large photos
without worrying about file size. For something the reader can drag and play
with, use an interactive visual instead — see page 1.3.