Allow temporary notes to be created at the main page (without having to put them into categories or anything)

[neongreen]

E.g. I just had an idea about what could go into the notes for acid-state, but there's no entry for acid-state and I'm too lazy to create one. Having some kind of scratchpad for notes would be nice.

(However, when a note is turned into a legitimate entry by someone else, it should linger on for some time so that the author would see that it was moved and not just deleted.)