synching with OSF repos

[thartbm]

For updating resources and sharing data, it would be cool if each experiment could be linked to an OSF repository that can then be shared between researchers.

When there is an OSF repo in the settings, PyVMEC should:

• probably first ask if people want to sync wit the repo, and if they do, ask for credentials (a username and either a password or an access token)
• when loading/starting the experiment, check if there are updated resources and download them for use
• maybe ask if new data should be downloaded (and then do it)
• not sure if the configuration json itself should be update as well
• when a participant is done, upload the data (should this be done automatically, or should this also be a question)

Alternatively, this is a menu with actions that gets active when an OSF repo is configured.