Update CHANGELOG.md (#2638)

Author: einarf

CHANGELOG.md

@@ -9,7 +9,8 @@ Arcade [PyPi Release History](https://pypi.org/project/arcade/#history) page.
 - Drop Python 3.9 support
 - Disable shadow window on all platforms to provide a consistent experience
 - Performance
-  - Improved performance of `arcade.SpriteList.remove()` and `arcade.SpriteList.pop()`
+  - Improved performance of `arcade.SpriteList.remove()` ~300%
+  - Improved `arcade.SpriteList.pop()` performance making it `O(1)` instead of `O(N)`
   - Improved performance of `arcade.hitbox.Hitbox.get_adjusted_points()` ~35%
   - Improved performance of `arcade.SpriteList.draw_hit_boxes()` ~20x
 - GUI
@@ -22,6 +23,8 @@ Arcade [PyPi Release History](https://pypi.org/project/arcade/#history) page.
   - Improve `arcade.gui.experimental.scroll_area.ScrollBar` behavior to match HTML scrollbars
 - Support drawing hitboxes using RBG or RGBA 
 - Fixed a bug causing some events to not trigger on the window's keyboard and mouse state handlers
+- Many documenation fixes and improvements
+- Various example fixes
 
 ## Version 3.0.2