Improve flow of command-line debugging

src/main.rs

@@ -87,6 +87,9 @@ fn main() -> Result<()> {
     if let Some(path) = args.rom {
         builder = builder.with_rom(&path);
     }
+    if args.debug_port.is_some() {
+        builder = builder.start_paused(true);
+    }
 
     ThreadBuilder::default()
         .name("Emulator".to_owned())