Add keyboard event handler. "Q" to quit program

src/main.rs

@@ -2,13 +2,15 @@ use bevy::prelude::*;
 
 mod breakout_plugin;
 mod hello_world_plugin;
+mod birdoids_plugin;
 
 use breakout_plugin::BreakoutPlugin;
 use hello_world_plugin::HelloPlugin;
+use birdoids_plugin::BoidsPlugin;
 
 fn main() {
     App::new()
         .add_plugins(DefaultPlugins)
-        .add_plugins(BreakoutPlugin)
+        .add_plugins(BoidsPlugin)
         .run();
 }