Detect packages that need to be installed before using yay.

packages/packages.sh

@@ -11,7 +11,16 @@ pacman_install() {
 }
 
 yay_install() {
-	yay -S --noconfirm --needed "$@"
+	packages=""
+	for package in "$@"; do
+		if ! pacman -Q "${package}" >/dev/null 2>&1; then
+			packages="${packages} ${package}"
+		fi
+	done
+	if [ ! -z "${packages}" ]; then
+		yay -S --noconfirm --needed ${packages}
+	fi
+	return 0
 }
 
 pacaur_install() {