add --version option

src/main.rs

@@ -12,8 +12,21 @@ use bevy::window::{Window, WindowMode, PrimaryWindow, CursorGrabMode};
 use bevy::diagnostic::FrameTimeDiagnosticsPlugin;
 use bevy::prelude::*;
 use bevy_embedded_assets::{EmbeddedAssetPlugin, PluginMode};
+use std::env;
 
 fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() > 1 {
+        if args[1] == "--version" || args[1] == "-v" {
+            let version = option_env!("CARGO_PKG_VERSION").unwrap();
+            let name = option_env!("CARGO_PKG_NAME").unwrap();
+            let homepage = option_env!("CARGO_PKG_HOMEPAGE").unwrap();
+            println!("{name} {version}");
+            println!("License: GNU GPL version 3: https://gnu.org/licenses/gpl.html");
+            println!("{homepage}");
+            return;
+        }
+    }
     if cfg!(debug_assertions) {
         App::new().add_plugins((
             OutFlyPlugin,