Add toolbar icon for Add note

[SamSandq]

I wanted to add this to the toolbar as I use it a lot, and noticed that it wasn't possible. Please add this option.

[SamSandq]

Just to add, the same for the iPad implementation; next to the icons for adding a link and an image.

[vincode-io]

I'll consider this for inclusion in a future release.

[vincode-io]

This has been added and will be in the upcoming 2.0.9 release.