Added missing "--" check for getopt

bash-folders-battery-hook.sh

@@ -91,6 +91,7 @@ main() {
             -h | --help )       usage; return 0;;
             -l | --low )        settings['low']="${2}"; shift;;
             -H | --high )       settings['high']="${2}"; shift;;
+            -- )                shift; break;;
             * )
                 printf '%s\n' "Unknown option: '${1}'" >&2
                 usage