Thank you! The formatting is from pull-left and pull-right. For a good example with the proper syntax see @carrieallen/ultimate-markdown-tutorial, the "Re-cap; Aligning left or right:" section.

You do have to play around with resizing the images - if they are too large then multiple images will stack on top of each other instead of being adjacent, and/or you won't be able to fit much text next to them.