This is a supper simple stitch pattern, though it may feel strange at first.
To make this edge, do one row of single crochet all the way around your project.
Next, without turning , chain 1, single crochet in each stitch around, working from left to right.
You are making a single crochet stitch, only backwards, in the reverse direction
you normally do your work.
Here is a great little video tut from Youtube to help you out.