Create folders, Edit folders, Move projects to a folder and Delete folders, can only be performed by users with admin rights.
Create a folder
Go to the Projects page.
Click New folder button.
Type folder's name and click Create button.
Move projects to a folder
On a project card click More Options icon > Add to folder.
On the popup screen select the folder to move to.
Click Save changes button.
Note: Folders can have unlimited number of projects in them.