Add MyPlate visualization

First of all, thank you for your great app.

It is really great to see the percentages of protein, carbs and fat. I would also like to see the percentages of protein, grains, vegetables and fruits so I can see if I am following the proportions of the [MyPlate aka Harvard plate](https://www.myplate.gov/eat-healthy/what-is-myplate). MyPlate is the next version of the nutrition pyramid.