CharacterBody2D "move_and_slide" method description should have a warning for floating character bodies

**Your Godot version:** 4.7

**Issue description:** The "move_and_slide" method description for "CharacterBody2D" says that it modifies velocity when a slide collision occurs which just isn't true for floating character bodies, as the velocity stays the same no matter what unlike grounded character bodies

**URL to the documentation page (if already existing):** https://docs.godotengine.org/en/stable/classes/class_characterbody2d.html

Open the linked CharacterBody2D documentation page and locate the move_and_slide method description. Add a warning explaining that floating character bodies do not modify velocity after a slide collision, unlike grounded character bodies. Done means the warning accurately distinguishes these behaviors and the documentation builds successfully.

Written by the indexing model from the issue text.