docs: install with pacman -Syu to avoid a partial upgrade

README.md

@@ -46,7 +46,7 @@ Server = https://git.trivk.dev/api/packages/tri/arch/$repo/$arch
 ```
 
 ```sh
-sudo pacman -Sy qtpotato
+sudo pacman -Syu qtpotato
 ```
 
 The package is built against Arch's current Qt and KDE Frameworks. If it breaks after a system