Thank you for creating this tool! I use it a lot with great enjoyment.

When benchmarking some services that have consistently quick response times, it can get hard to visually parse the small fractions of seconds in the output.
It would be great if oha could support automatically or manually selecting the time unit for displaying the benchmark results.

This feature request is inspired by another amazing tool, hyperfine.
It automatically selects the appropriate time unit, based on the mean time of the benchmark result.
The --time-unit flag option can be used to manually set the time unit to be used.

// snippet from `hyperfine --help`

  -u, --time-unit <UNIT>
          Set the time unit to be used. Possible values: microsecond,
          millisecond, second. If the option is not given, the time unit is
          determined automatically. This option affects the standard output as
          well as all export formats except for CSV and JSON.

I'd love to hear if this is a feature you would like to have in your tool.