1. Add the image at `content/posts/post-title/image-name.png`
2. Add markdown that references it, like ``
3. Build and push to main, and then the image is available in minutes at `https://<host>/posts/post-title/image-name.png`
Part of the reason I use Hugo is because it's so low friction — the hard part is the writing (and writing consistently), and keeping everything else easy is key.