update README

README.md

@@ -6,7 +6,8 @@ create interfaces including peers. Configuration is done via pillar (see below).
 **Attention**: WireGuard is not yet included in the linux mainline kernel. Also,
 the installation is different on every distribution and sometimes you even have
 to include unstable/testing branches. For now, please
-[install WireGuard](https://www.wireguard.com/install/) yourself.
+[install WireGuard](https://www.wireguard.com/install/) yourself. You can use
+this formula afterwards.
 
 # Installation