update notes and complete build script

scripts/ablrun-appimage

@@ -8,6 +8,10 @@ then
     echo "    You have to ensure input file IS an appimage, for this script"
     echo "    does not check. If you input other files, It will become"
     echo "    unpredictable."
+    echo
+    echo "    There is a more convenient script to handle both normal executable"
+    echo "    and appimage, called ablrun."
+    echo "    usage: ablrun [command [arguments ...]]"
     exit
 fi