index.html: added comments to the functions and modified formatting of buttons
index.html: added comments to the functions and modified formatting of buttons


Former-commit-id: 99857015e819f6f3e6ff98f25d6eda654c3f48df
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox