Delete a sidebar section; its lists return to the default section

Make, rename, delete, hide or show a sidebar section (the groups the user's lists stand in; list_lists and get_context carry them in order). create makes an empty section at the end, or answers the section that already wears the name; rename renames one (the default section too — its name is Lists until renamed; "" puts Lists back); delete removes a section and its lists return to the default section (the default section is never deleted); hide / show fold a section out of or back onto the sidebar on every device. To put a list INTO a section use create_list or update_list with section.