doc: Fix invalid [enum] uses

doc/classes/AnimationPlayer.xml

@@ -238,7 +238,7 @@
 			The default time in which to blend animations. Ranges from 0 to 4096 with 0.01 precision. Default value: [code]0[/code].
 		</member>
 		<member name="playback_process_mode" type="int" setter="set_animation_process_mode" getter="get_animation_process_mode" enum="AnimationPlayer.AnimationProcessMode">
-			The process notification in which to update animations. Default value: [enum ANIMATION_PROCESS_IDLE].
+			The process notification in which to update animations. Default value: [code]ANIMATION_PROCESS_IDLE[/code].
 		</member>
 		<member name="playback_speed" type="float" setter="set_speed_scale" getter="get_speed_scale">
 			The speed scaling ratio. For instance, if this value is 1 then the animation plays at normal speed. If it's 0.5 then it plays at half speed. If it's 2 then it plays at double speed. Default value: [code]1[/code].

doc/classes/AnimationTreePlayer.xml

@@ -618,7 +618,7 @@
 			Once set, Animation nodes can be added to the AnimationTreePlayer.
 		</member>
 		<member name="playback_process_mode" type="int" setter="set_animation_process_mode" getter="get_animation_process_mode" enum="AnimationTreePlayer.AnimationProcessMode">
-			The thread in which to update animations. Default value: [enum ANIMATION_PROCESS_IDLE].
+			The thread in which to update animations. Default value: [code]ANIMATION_PROCESS_IDLE[/code].
 		</member>
 	</members>
 	<constants>

doc/classes/PackedScene.xml

@@ -52,7 +52,7 @@
 			<argument index="0" name="edit_state" type="int" enum="PackedScene.GenEditState" default="0">
 			</argument>
 			<description>
-				Instantiates the scene's node hierarchy. Triggers child scene instantiation(s). Triggers the [enum Node.NOTIFICATION_INSTANCED] notification on the root node.
+				Instantiates the scene's node hierarchy. Triggers child scene instantiation(s). Triggers [Node]'s [code]NOTIFICATION_INSTANCED[/code] notification on the root node.
 			</description>
 		</method>
 		<method name="pack">

doc/classes/Tween.xml

@@ -14,7 +14,7 @@
 		tween.start()
 		[/codeblock]
 		Many methods require a property name, such as "position" above. You can find the correct property name by hovering over the property in the Inspector.
-		Many of the methods accept [code]trans_type[/code] and [code]ease_type[/code]. The first accepts an [enum TransitionType] constant, and refers to the way the timing of the animation is handled (see [code]http://easings.net/[/code] for some examples). The second accepts an [enum EaseType] constant, and controls the where [code]trans_type[/code] is applied to the interpolation (in the beginning, the end, or both). If you don't know which transition and easing to pick, you can try different [enum TransitionType] constants with [enum EASE_IN_OUT], and use the one that looks best.
+		Many of the methods accept [code]trans_type[/code] and [code]ease_type[/code]. The first accepts an [enum TransitionType] constant, and refers to the way the timing of the animation is handled (see [code]http://easings.net/[/code] for some examples). The second accepts an [enum EaseType] constant, and controls the where [code]trans_type[/code] is applied to the interpolation (in the beginning, the end, or both). If you don't know which transition and easing to pick, you can try different [enum TransitionType] constants with [code]EASE_IN_OUT[/code], and use the one that looks best.
 	</description>
 	<tutorials>
 	</tutorials>