portable shebang

.local/bin/ifinstalled

@@ -1,3 +1,3 @@
-#!/bin/sh
+#!/usr/bin/env sh
 # If $1 command is not available, error code and notify.
 command -v "$1" >/dev/null || { notify-send "📦 $1" "must be installed for this function." && exit 1 ;}