Update README.md

JingShing · web-flow · commit 33a3dbac8b56 · 2022-08-03T23:00:18.000+08:00
diff --git a/README.md b/README.md
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 # Pygame_sdl2-Multiwindow-class
 A window class. You can use in pygame to create multi window. since pygame can only had one window at a time.
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+You may need my other project ModernGL import into this project to ensure run successful.
