Function mandelbrot::main

fn main()

Main function.

1. Creates a window, a surface to draw on.
2. Gets a GPU device from wgpu.
3. Creates the different separate views you can change to.
4. Starts watcher thread that listens to OS write events and reloads fragment shader while the program is running.
5. Starts the event loop, in which it passes user input events to the current view using the SwitchableViewManager.