"Animation Track types" page doesn't specify that some track types won't work backwards

[Meorge]

Your Godot version: 4.5

Issue description: The page describing Animation Track types doesn't point out that Animation Playback tracks will not play when the animation is played with play_backwards(). I'd made an animation that used these kinds of tracks, and then was confused because they were not playing correctly (or at all) when I used play_backwards() on them.

It'd be good to have this page specify that Animation Tracks, and likely other track types as well, will not work in reverse or with different speed scales.

URL to the documentation page: https://docs.godotengine.org/en/stable/tutorials/animation/animation_track_types.html