This is an example of an image with a shape-outside. The image is already transparent so I don't need to clip it as well. The effect really only comes into play if there is enough text to wrap around some of the shapes, so here is a little bit more text. The image is of a contraption from the Starcraft universe, and the copyright belongs to Blizzard Entertainment. I use it here only for educational purposes since it's pointy.
Your browser devtools likely have a WYSIWYG shapes editor that helps make the correct polygon function. Add a basic polygon yourself and then click the shapes editor to get started. Below is how it looks in Firefox 67.