Renaming notes

Renaming a note through settle comes with the benefit that all links to the
former title are updated, which means that links (almost) never break.

You can rename a note by using the settle sync --rename <FROM> <TO>. Titles
here are matched exactly, as using regex could match multiple notes.

Here are two examples:

  - settle sync --rename "PSYCHOLOGY" "Psychology" renames "PSYCHOLOGY" to
    "Psychology"
  - settle sync --rename "Neuroology" "Neurology" renames the note called
    "Neuroology" to "Neurology"

Errors

  - if the specified old title doesn't exist, then an error is returned
  - if there is already a note with the new title provided, then an error is
    returned and the overwrite is prevented.
