Summarize:

Leaving them on the wire rack for this part of the process will allow any excess chocolate to drip down onto your baking sheet instead of puddling around the edges of each macaroon. Once the chocolate is set, they are ready to serve.
Put the chocolate chips into microwave-safe bowl and microwave them on medium heat for 30 seconds. Stir the chocolate with a small spoon to help mix the melted parts with the solid chips. Repeat the heating at 30-seconds intervals until the chocolate is completely melted. Using a small spoon, drizzle your melted chocolate over the tops of the cooled macaroons. While still sitting on the wire rack, place them in the fridge to allow the chocolate to harden.