The BottomAppBar when given in the Scaffold gets hidden when the
keyboard is visible. We had hacked around that by translating its
position, however that resulted in the cursor at the bottom being hidden
when we were typing a long note.
It is not just part of the body of the scaffold.
Also converted many functions into widgets.
This adds a '+' button to the NoteEditor which allows you to add an
image from either the Gallery or Take a photo. It then accordingly adds
updates markdown.
The file is added in the same directory as the note for now.
Related to #10
