a first great contribution is already what they are doing: exploring how the platform can be used in a particular context of application, that is assistive robotics. Here what will be useful to the community is if they can report through the forum what are the targets, how they use or transform the platform, discussing ideas of how it could be improved to be even better suited for these kinds if uses.
Then, another thing extremely useful would be to build repertoires of behaviours for the torso in such a context and share them with the community. The best way to do this is would be to build tutorials as an IPython notebook allowing for example other students like them to take on their work for another student project.
When this will be in an advanced form, it could be useful to include a page about the project on the Poppy front web page, e.g. like for the Marionnettes Electriques (https://www.poppy-project.org/project/marionnettes-electriques/)
Also, for installation guides, tutorials about pypot, etc, there are many ways in which they can be improved
And one of the challenges is also to provide contents and tutorials in French (and other languages),
So many areas for contribution