CharacterSpriteBehavior: Automatically assign character

In the same way as we assign sprite if not set and the parent is an
AnimatedSprite2D, do it to the parent's parent if it is a
CharacterBody2D.

The rationale is that usually this is what you'll have in the Scene
Tree, while at the same time it keeps being configurable.

Also update the format in the existing documentation comment.

Author: manuq

scenes/game_logic/character_sprite_behavior.gd

@@ -9,16 +9,19 @@ extends Node2D
 ## to the velocity of [member character].
 
 ## The [member CharacterBody2D.velocity] is used to change the [member sprite].
+## [br][br]
+## [b]Note:[/b] If the grandparent node is a CharacterBody2D and this isn't set,
+## the grandparent node will be automatically assigned to this variable.
 @export var character: CharacterBody2D
 
 ## Whether to play the sprite animations or not. If not, the only thing that will happen is that
 ## the sprite will be flipped horizontally according to the velocity of [member character].
 ## Use this when using more advanced animation through an AnimationPlayer node.
 @export var play_animations: bool = true
 
-## The controlled sprite.[br][br]
-##
-## [b]Note:[/b] If the parent node is a AnimatedSprite2D and sprite isn't set,
+## The controlled sprite.
+## [br][br]
+## [b]Note:[/b] If the parent node is a AnimatedSprite2D and this isn't set,
 ## the parent node will be automatically assigned to this variable.
 @export var sprite: AnimatedSprite2D:
 	set = _set_sprite
@@ -29,6 +32,8 @@ var _is_character_running: bool = false
 func _enter_tree() -> void:
 	if not sprite and get_parent() is AnimatedSprite2D:
 		sprite = get_parent()
+	if not character and get_parent() and get_parent().get_parent() is CharacterBody2D:
+		character = get_parent().get_parent()
 
 
 func _set_sprite(new_sprite: AnimatedSprite2D) -> void: