Skills are easy to add so that they can be allocated to profiles. From the detail view press

Name and describe a particular skill here. Don't forget press

To update the icon open the skill in the detail view and press  

To upload drag a file over or press upload

Allocate Skills to users

Enter the profile from People & Teams in the Administration view. 

Select Skills from the Profile Menu. Press  

Toggle on all the skills that are applicable for that user.

Skills will appear in a users profile