Docker can be installed through Fedora's standard repos, but it was renamed to moby-engine.

It can be installed with dnf install moby-engine.

See this issue for more information.

Here is a list of shortcuts on how to create a screenshot in GNOME 3:

• Prt Sc: whole desktop (all monitors)
• Alt + Prt Sc: current window
• Shift + Prt Sc: selected area

By pressing Ctrl simultaneously, the screenshot will be copied into the clipboard instead of being saved as a file.

Check the official documentation for more information.