Update README.md

README.md

@@ -16,7 +16,7 @@ Pygbag does not track usage at all, not even for statistical purposes. If you li
 - Put the import statements of complex packages in order (but numpy first) at the top of `main.py`.
 - Avoid using CPython's standard library for web operations, GUI (like tkinter), or I/O as it is very synchronous/platform-specific and will probably stay that way. In terms of GUI alternatives, [pygame_gui](https://pypi.org/project/pygame_gui) works on top of [pygame-ce](https://pyga.me), [Panda3D](https://www.panda3d.org/) provides [directgui](https://docs.panda3d.org/1.10/python/programming/gui/directgui/index) and Harfang3D provides imgui. They are all cross-platform.
 - You can add a square image file named `favicon.png` in your game's root folder to make Pygbag use it as the web package's favicon.
-- Make sure all audio files are in OGG format, and all files are compressed. (that is, not in WAV/AIFF)
+- Make sure all audio files are in OGG format, and all files are compressed. (that is especially **not in WAV/AIFF/MP3 format**)
 - Avoid raw formats like BMP for your image assets, they are too big for web use; use PNG/WEBP or JPG instead.
 
 - Do not use filenames like `*-pygbag.*`  that pattern is reserved for pygbag internal use (optimizing pass).