add an example for async file loading

examples/async_file_loading.rs

@@ -0,0 +1,41 @@
+use macroquad::{
+    audio::{load_sound, play_sound, PlaySoundParams},
+    prelude::*,
+};
+
+#[macroquad::main("Audio")]
+async fn main() {
+    set_pc_assets_folder("examples");
+
+    let _coroutine = coroutines::start_coroutine(async move {
+        let sound_handle = load_sound("sound.wav").await;
+
+        //to simulate it taking a while to load this file, lets do this in a nice loop :)
+
+        for v in 0..10000 {
+            load_sound("sound.wav").await.unwrap();
+            if v % 10 == 0 {
+                println!("Loaded the file {v} times")
+            }
+        }
+
+        println!("Finished loading sound. Playing...");
+        match sound_handle {
+            Ok(music) => play_sound(
+                &music,
+                PlaySoundParams {
+                    looped: true,
+                    volume: 1.,
+                },
+            ),
+            Err(e) => eprintln!("Failed to load epic music :( -- {e}"),
+        }
+    });
+    let mut x = 0.;
+    let speed = 20.;
+    loop {
+        x += speed * get_frame_time();
+        draw_rectangle(x, 10., 20., 20., GREEN);
+        next_frame().await;
+    }
+}