Notes structure format

How are notes managed in Melibea and what are the logical contents of a note besides the main area where the user can write.

* Melibea stores notes in a structure called Page. The user can write in pages. Pages have the following information:
** Title: user can set the title for each note. It is displayed on top of the page and on the pages tree, plus it identifies the note against others.
** Creation date: date the user created the note.
** Last modification date: date the user last edited the note.
** Hashtags: user can set hashtags for a note. User can search or filter notes given a hashtag.
** Content: actual text content for the note.
* Pages are contained in a Folder. A Folder can contain Pages and other Notes. Pages have the following structure:
** Name: name of the folder.
** Description: some short description of the folder.
** Creation date: date the user created the folder.
** List of pages.
* Folders are contained in a Library. A library is just a special Folder called `root`, but it's considered a separated entity, as probably in the future it will have special features.