[Docs] Add user guide

[RightWrite]

Hi,

I realize the readme & app description have basic usage suggestions.

What about a user manual?

I can create an md file &/or PDF with screen images, walking the user through menu options, step-by-step.

Then, a link to the user guide can be placed in the app description.

Let me know what you think.

good day

[pastthepixels]

Hey! That's be great actually considering there's been a bit of confusion from people using FreePaint without any experience using any other vector graphics drawing app. I've had to answer a few questions with a "yeah, that's intended functionality I copied over from Inkscape", or "that's near impossible because of the way FreePaint works". Something like a wiki page would be amazing!!