You can easily organize repositories by adding and removing them.
Add a repository
To add a repository, click on Add repository
button on home screen. To learn different ways to add repository, go to Add an existing repositroy.
Remove a repository
To remove an item from the list of repositories, click on the gear icon, you will re-directed to settings page, click on the Remove button in the danger zone.
You can add the repository again, once you remove it.