[feature request] seqkit subseq with --circular option?

[xinehc]

Hi Wei,

I wonder would it be possible to add a --circular option also to seqkit subset?

I am currently using seqkit subset to extract the flanking regions of some genes with bed files. Some genes are located near the boundary of circular genomes so the flanks get truncated. It would be nice to have this option so that I don't need to manually concatenate the sequences multiple times before annotating genes. It would be even nicer if seqkit subset could differentiate linear/circular genomes with a user specified list or bed. For example:

seq_a    linear
seq_b    circular
...