Improve the VisibilityNotifier and VisibilityEnabler class descriptions

(cherry picked from commit ce57cc43dd)

doc/classes/VisibilityEnabler.xml

@@ -5,7 +5,8 @@
 	</brief_description>
 	<description>
 		The VisibilityEnabler will disable [RigidBody] and [AnimationPlayer] nodes when they are not visible. It will only affect other nodes within the same scene as the VisibilityEnabler itself.
-		[b]Note:[/b] VisibilityEnabler uses an approximate heuristic for performance reasons. It doesn't take walls and other occlusion into account. If you need exact visibility checking, use another method such as adding an [Area] node as a child of a [Camera] node.
+		If you just want to receive notifications, use [VisibilityNotifier] instead.
+		[b]Note:[/b] VisibilityEnabler uses an approximate heuristic for performance reasons. It doesn't take walls and other occlusion into account. The heuristic is an implementation detail and may change in future versions. If you need precise visibility checking, use another method such as adding an [Area] node as a child of a [Camera] node and/or [method Vector3.dot].
 		[b]Note:[/b] VisibilityEnabler will not affect nodes added after scene initialization.
 	</description>
 	<tutorials>

doc/classes/VisibilityEnabler2D.xml

@@ -5,7 +5,8 @@
 	</brief_description>
 	<description>
 		The VisibilityEnabler2D will disable [RigidBody2D], [AnimationPlayer], and other nodes when they are not visible. It will only affect nodes with the same root node as the VisibilityEnabler2D, and the root node itself.
-		[b]Note:[/b] For performance reasons, VisibilityEnabler2D uses an approximate heuristic with precision determined by [member ProjectSettings.world/2d/cell_size]. If you need exact visibility checking, use another method such as adding an [Area2D] node as a child of a [Camera2D] node.
+		If you just want to receive notifications, use [VisibilityNotifier2D] instead.
+		[b]Note:[/b] For performance reasons, VisibilityEnabler2D uses an approximate heuristic with precision determined by [member ProjectSettings.world/2d/cell_size]. If you need precise visibility checking, use another method such as adding an [Area2D] node as a child of a [Camera2D] node.
 		[b]Note:[/b] VisibilityEnabler2D will not affect nodes added after scene initialization.
 	</description>
 	<tutorials>

doc/classes/VisibilityNotifier.xml

@@ -5,7 +5,8 @@
 	</brief_description>
 	<description>
 		The VisibilityNotifier detects when it is visible on the screen. It also notifies when its bounding rectangle enters or exits the screen or a [Camera]'s view.
-		[b]Note:[/b] VisibilityNotifier uses an approximate heuristic for performance reasons. It doesn't take walls and other occlusion into account. If you need exact visibility checking, use another method such as adding an [Area] node as a child of a [Camera] node.
+		If you want nodes to be disabled automatically when they exit the screen, use [VisibilityEnabler] instead.
+		[b]Note:[/b] VisibilityNotifier uses an approximate heuristic for performance reasons. It does't take walls and other occlusion into account. The heuristic is an implementation detail and may change in future versions. If you need precise visibility checking, use another method such as adding an [Area] node as a child of a [Camera] node and/or [method Vector3.dot].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/VisibilityNotifier2D.xml

@@ -5,7 +5,8 @@
 	</brief_description>
 	<description>
 		The VisibilityNotifier2D detects when it is visible on the screen. It also notifies when its bounding rectangle enters or exits the screen or a viewport.
-		[b]Note:[/b] For performance reasons, VisibilityNotifier2D uses an approximate heuristic with precision determined by [member ProjectSettings.world/2d/cell_size]. If you need exact visibility checking, use another method such as adding an [Area2D] node as a child of a [Camera2D] node.
+		If you want nodes to be disabled automatically when they exit the screen, use [VisibilityEnabler2D] instead.
+		[b]Note:[/b] For performance reasons, VisibilityNotifier2D uses an approximate heuristic with precision determined by [member ProjectSettings.world/2d/cell_size]. If you need precise visibility checking, use another method such as adding an [Area2D] node as a child of a [Camera2D] node.
 	</description>
 	<tutorials>
 	</tutorials>