DOC: added figures for website
DOC: added figures for website

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Former-commit-id: 0f8dbfb7a225422359b876456f0a234b287613d0
Former-commit-id: 2e133aeb79514a0f23bce4514431aeacc0a72eaf
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox