Update README.md

Add screenshot and change wording.

README.md

@@ -1,8 +1,10 @@
 # FBSim
 
-Game-like football simulation environment for trying out AI ideas, written in Rust.
+Retro-looking game-like football simulation environment for trying out AI ideas, written in Rust.
 
-I wrote all of this in my free time to learn a bit about Rust and game development. The code is very scarcely documented and there is no testing at all. Consider yourself warned.
+I wrote all of this in my free time to learn a bit about Rust and game development. The code is very scarcely documented and there is no testing at all. Use at your own risk.
+
+![Screenshot of running game](screenshots/2020-11-20_17-09-47.png)
 
 ## Instructions
 
@@ -28,7 +30,7 @@ If you want to write your own engine, the way to do it is:
 1. Create a structure implementing the trait `src/engines/engine.rs::Engine`. (Look at `src/engines/basic.rs` implementations as a guide)
 2. Add it to the default engine registry in `src/resources/engine_registry.rs::EngineRegistry::default`.
 3. Modify `assets/sprites/player.ron` so that `entities.data.extras.player.robot.logic_module` is `EngineRunner("<registered_name_for_your_engine>").
-4. Run `cargo run` and see your agents play against the default `Basic` engine!
+4. Run `cargo run` and see your agents play against the default `Basic` engine! (You can change `enemy.ron` to make them use a different engine as well).
 
 ## Roadmap