DOC: Update outputs.rst to indicate hemi entity precedes space

[askieslinger]

Hi,

I have noticed the order of the bids identifiers 'hemi' and 'space' for func.gii outputs is swapped in the documentation compared to my real output and compared to the BIDS guidelines.

fmriprep/docs/outputs.rst

Line 192 in 0ed3a93

sub-<subject_label>_[specifiers]_space-<space_label>_hemi-[LR]_bold.func.gii

`Discrete surface segmentations (sometimes called parcellations) of cortical structures MUST be stored as GIFTI label files, with the extension .label.gii. For combined volume/surface spaces, discrete segmentations MUST be stored as CIFTI-2 dense label files, with the extension .dlabel.nii.

Template:

<pipeline_name>/
sub-/
anat/
<source_entities>[_hemi-{L|R}][_space-][_atlas-][_res-][_den-]_dseg.{label.gii|dlabel.nii}

`(https://bids-specification.readthedocs.io/en/stable/05-derivatives/03-imaging.html#discrete-surface-segmentations)

This has possibly led to difficulties with the nilearn fmriprep interface and the order should perhaps be made clearer.
Thank you.

[effigies]

That's unfortunate. I think hemi makes sense after space, as you'd want to group pairs of related images together lexically.

[effigies]

Ah, unfortunate or not, we do write hemi- first: https://github.com/nipreps/fmriprep/blob/master/.circleci/ds005_bids_outputs.txt

So as you say, we just need to update our docs.

xref #2620