Slice time correction defaults

[hspopal]

Hi,

It would be nice to have a feature for implementing slice time corrections for first level modeling. Or, at least to provide some documentation about how nilearn treats slice time corrections and how to adjust our data ,if slice time correction was done, to be compatible with nltools. Some (like me) may not realize that different softwares have different views and defaults on slice time correction (e.g. default of fmriprep is to do it, nltools does not do it by default).

Thank you!