Keeping the database up to date

Since note editing isn't done with settle,
the database needs to be updated quite frequently to always have the correct
metadata.

Fortunately, updating the database is fairly straightforward:

  - settle sync --generate updates every database entry, based on what files are
    on the filesystem. For example, if you delete a note from update to update,
    then its entry won't appear in the new one.

  - settle sync --update <PATH> takes the path (absolute or relative) to a note
    file, whose corresponding database entry is updated. Keep in mind that if
    the provided path is outside of the Zettelkasten, or it doesn't exist, then
    an error is returned.
