extend PATH in pam_environment instead of zsh config

This way, the extended PATH variable is available for the whole
session and not just for the zsh session.

setup.sh

@@ -40,7 +40,10 @@ link()
 	[ -z "${dryrun+x}" ] && ln -sf "$src" "$dst"
 }
 
+# generic config
+link pam_environment ~/.pam_environment
 
+# application-specific config
 if installed vim; then
 	echo "Setting up vim:"