Allow the user to use the column names

[remi-braun]

For my usecase it has been proven useful to plot the column names instead of the chunk_size:

[remi-braun]

Maybe linked to #34 ?

[gecko984]

Hey Rémi, thank you for the PR. tThis is indeed exactly what is suggested in issue #34
I'm not too sure about the implementation you suggested, because it will prove useful in a very small number of cases - namely, when all the sets are really small, like 1-2 items, and also the items' string representatation must be short. I think, at least the items names should be rotated 90 degrees. And the existing parameter rotate_col_annotations won't work here, because it will rotate the whole ', '.join(names) instead each of the names individually.

Also I wrote a couple more things in the code comments, otherwise I'll happily accept this PR

[remi-braun]

Hello,
I made another commit to take your comment into account, but sadly I haven't anytime left to spend on this PR.
Feel free to modify it as you want 😉