[Feature Request]: Ability to highlight specified diff line numbers range

Hi,

I'd like to highlight (as in white terminal background) specific range of lines in a side-by-side diff.

I'm using difftastic likeGIT_EXTERNAL_DIFF=difft DFT_DISPLAY=side-by-side-show-both git diff 27d81802e8fa9204e131205424edaab82308ce5e\^ 27d81802e8fa9204e131205424edaab82308ce5e --unified=0 and am only interested in one of the hunks despite a git commit having multiple files and multiple diff hunks.

My current approach is to grep the line numbers from difft's output and pipe to bat --highlight=... but that's horribly inexact and breaks in all sorts of cases.

What it could look like instead is difft --highlight=<FILENAME>:<START-LINE-NUMBER>:<COUNT>. difft would then highlight <COUNT> lines, starting at <START-LINE-NUMBER> in a filename <FILENAME>. This kind of spec would mirror the format present in the unified diff format. The line number is expressed as n-th line in the file <FILENAME>, starting from 1.

Thanks!