REF: added available parameters to sct_propseg
REF: added available parameters to sct_propseg

Former-commit-id: 1c496176baab0230374b649cb7fb31b5e46f9cd0
Former-commit-id: bf9efd942abf8090c8793d078b3d6e0ed77661d5
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox