API Documentation
Postman has an API Documentation too. You can click on the ellipsis next to the collection name to open more actions. Then select "View Documentation".
You can edit the name of API requests, add description to each, provide examples, etc. Once ready, click on the "Publish" button.
Postman will generate a stylish HTML documentation of your API. Here is the one I generated for the API we've worked on in this module.