note/add - Creates a new note.

Method parameters:
text - The text of the note.
encrypt_in_listings - Whether the note should be encrypted in listings.
password_protect - Whether the note should be password-protected. This option is available with a password-authenticated session only.
tags - A space-separated list of tags.

Returns a JSON document of the following format:
<number> - The ID of the newly created note.

Expected errors:
ENTER_TEXT - The text is empty.
TOO_MANY_TAGS - More than 5 tags given.
CANNOT_PASSWORD_PROTECT - A password-authenticated session is required to password-protect the note.