Implement animation root motion deltas (#84)

Implements root motion and adds a dash attack.

Reviewed-on: #84
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

src/fighter/animation.rs

@@ -100,4 +100,5 @@ pub enum AnimKind {
     AttackDownTilt,
     AttackNeutralAir,
     AttackForwardAir,
+    AttackDash,
 }