Allow themes to use a custom icon theme via the icons.theme file

They get to pick from the Yaru color set

migrations/1754047941.sh

@@ -0,0 +1,9 @@
+echo "Add icon theme coloring"
+
+if ! yay -! yaru-icon-theme &>/dev/null; then
+  yay -S --noconfirm yaru-icon-theme
+
+  if [[ -f ~/.config/omarchy/current/theme/icons.theme ]]; then
+    gsettings set org.gnome.desktop.interface icon-theme "$(<~/.config/omarchy/current/theme/icons.theme)"
+  fi
+fi