Refactor code

[Edo78]

Right now there is an object passed to the createNote function, another object used for the frontmatter and a third one passed to the rendering of the template.

All three of them have a lot of things in common and are computed from other properties.

I'd like to have a single object so with just the frontmatter from an existing note I can create another (like the "in memory" one I use to fix #37 ) and this way I can easily add more field and have an easier way to do #26