Support for alpine linux

detects if cp and grep are the non BusyBox versions

generate_config.sh

@@ -1,5 +1,14 @@
 #!/bin/bash
 
+if grep --help 2>&1 | head -n 1 | grep -q -i "busybox" ; then
+  echo "BusybBox grep detected, please install gnu grep, \"apk add --upgrade grep\""
+  exit 1
+fi
+if cp --help 2>&1 | head -n 1 | grep -q -i "busybox" ; then
+  echo "BusybBox cp detected, please install coreutils, \"apk add --upgrade coreutils\""
+  exit 1
+fi
+
 if [[ -f mailcow.conf ]]; then
   read -r -p "A config file exists and will be overwritten, are you sure you want to contine? [y/N] " response
   case $response in