Update README.md

Author: maddie

README.md

@@ -111,6 +111,7 @@ GLOBAL OPTIONS:
    --bytes                        Display values in bytes instead of bits. Does not affect
                                   the image generated by --share, nor output from
                                   --json or --csv (default: false)
+   --mebibytes                    Use 1024 bytes as 1 kilobyte instead of 1000 (default: false)
    --distance value               Change distance unit shown in ISP info, use 'mi' for miles,
                                   'km' for kilometres, 'NM' for nautical miles (default: "km")
    --share                        Generate and provide a URL to the LibreSpeed.org share results