Getting started with game mechanisms

Let's start with the UI rendering first and then add the font management in order to display the game information in real time.

Rendering UI

With the current code base, very few changes are required in order to be able to have a fully working Tetris.

Rendering initialization

For now, the main function is very small. First, let's add the following lines at the top of the function:

    let sdl_context = sdl2::init().expect("SDL initialization 
      failed");
    let video_subsystem = sdl_context.video().expect(&quot...