spa: properly document the whole crate
Let's try to improve our documentation a bit.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
Reminder: GitLab will be down for maintenance Monday June 03, from approx 10am UTC for roughly 48 hours. This is for a major gitlab upgrade which requires a DB migration. See the tracker issue for more informations.
Let's try to improve our documentation a bit.