This feature is good for those of you that well... archive resources. All jokes aside, de-archiving resources to make them appear in your Gantt chart area is as easy as archiving them.
Must-know About This Feature
If you de-archive a Resource, it will be a part of your Resource count. All of its Tasks will be de-archived with it. Make sure your current plan allows it.
De-archive Resources
Open the Resource List
You'll find it on the Sidebar.
Click on "Archived" on top right
There, you'll see all the Resources that you have archived
Select Resources
You can select one or many.
Click on "De-archive"
The Resources will appear in the Gantt chart area along with their Tasks.
Before de-archiving, make sure you have upgraded to a package that allows you to have this amount of resources.