REF: changed description on doc
REF: changed description on doc

Former-commit-id: e0964263d460835d50aeeefc7a74b1cf3079160b
Former-commit-id: a94e0d1acd16383099a9c1d5a8e0448551526794
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox