Improve v0.12 styling #35
Description
Colors, fonts in v0.12 are not optimal. There are 4 color schemes - white and black with high contrast and "solarised" versions. Have a look at VisUAL https://salmanarif.bitbucket.io/visual/ for a similar but not identical example of styling. VisUAL2 is not as consistent or attractive as VisUAL.
These changes can all be made in the app CSS, mostly vistally.css, but also monaco-init.js. The references to other css files are probably not needed and should be cleaned up - with necessary stuff extracted to vistally and the other big CSS files (used as tempates initially for various GUI elements) removed.
Visual studio has a good GUI for playing with CSS with a lot of code completion, auto color picking, etc. However the project CSS currently does not pass CSS linting. this should be fixed if possible. I'm not sure if possible because the CSS uses CSS variables defined under :root to communicate with F# code.
Also the CSS classes should be better documented.