Adds a group to the shortcuts section.
This is the programmatic equivalent to using gtk.builder.Builder and a <child> tag to add the child.
Adding children with the gtk.box.Box API is not appropriate, as gtk.shortcuts_section.ShortcutsSection manages its children internally.
the gtk.shortcuts_group.ShortcutsGroup to add
Adds a group to the shortcuts section.
This is the programmatic equivalent to using gtk.builder.Builder and a <child> tag to add the child.
Adding children with the gtk.box.Box API is not appropriate, as gtk.shortcuts_section.ShortcutsSection manages its children internally.