54: Document how to run examples r=grovesNL a=rukai
I had assumed the triangle example wasn't functional yet, because I didn't realize I had to specify a feature. I only realized it was supposed to work when I saw a screenshot of the cube example.
I'm not sure what the future is of the triangle example? Will it remain outside of the gfx-examples folder?
Co-authored-by: Rukai <rubickent@gmail.com>