Enhancement Request for csvtk summary

[harish0201]

Prerequisites

• [ YES] make sure you're are using the latest version by csvtk version
• [ YES] read the usage

Describe your issue

• describe the problem
  Isn't really a problem, but an enhancement request: Can we use index ranges for performing functions?

for command purposes, I'm taking "uniq" as example here:
csvtk summary -t -g f1 -f 2:uniq,3:uniq,4:uniq < data.tsv

Request it format like how unix cut does: cut -d$'\t' -f2-4 < data.tsv

csvtk summary -t -g f1 -f 2-4:uniq < data.tsv

• provide a reproducible example
  where data.tsv is the following

name	C2	C3	C4
bob	1	3	5
bob	3	4	8
rick	2	3	7
lolo	1	2	3

This should be the outcome of the command: csvtk summary -t -g name -f C2:uniq,C3:uniq,C4:uniq

name	C2:uniq	C3:uniq	C4:uniq
bob	1; 3	3; 4	8; 5
lolo	1	2	3
rick	2	3	7

However, the same could be written as: csvtk summary -t -g name -f C2-C4:uniq or csvtk summary -t -g 1 -f 2-4:uniq
going by either digital names or column index.

If the above is already available, can you share the syntax? I've been wrecking my head over it!

Thank you for the wonderful tool!