How to add Icons for every Doc

How to add icons for every Doc?

Here is an example of how it looks on another page:
https://support.yithemes.com/hc/en-us

And here is how it looks on my page (without icons):
[ redundant link removed ]
Thanks,
Davor

• This topic was modified 5 years, 3 months ago by Jan Dembowski.
• This topic was modified 5 years, 3 months ago by Jan Dembowski.

The page I need help with: [log in to see the link]