When creating or editing a list, the group selection dropdown will only appear if the user selects "group" as the curation option (or it is already selected).
- fix typo in bookwyrm.js comments
- add data-hides trigger for hiding elements after they have been unhidden, where simple toggles are not the right approach
Allows 'group' to be blank when saving a list.
Removes the 'group' field when saving a list with curation other than 'group' - this stops the list "sticking" to a group after it is changed from group curation to something else.
