doc: Timer.autostart resets to false on start

Fixes #35289.

doc/classes/CPUParticles2D.xml

@@ -361,7 +361,7 @@
 			Particles will be emitted at a position chosen randomly among [member emission_points]. Particle velocity and rotation will be set based on [member emission_normals]. Particle color will be modulated by [member emission_colors].
 		</constant>
 		<constant name="EMISSION_SHAPE_MAX" value="5" enum="EmissionShape">
-                        Represents the size of the [enum EmissionShape] enum.
+			Represents the size of the [enum EmissionShape] enum.
 		</constant>
 	</constants>
 </class>

doc/classes/Timer.xml

@@ -37,6 +37,7 @@
 	<members>
 		<member name="autostart" type="bool" setter="set_autostart" getter="has_autostart" default="false">
 			If [code]true[/code], the timer will automatically start when entering the scene tree.
+			[b]Note:[/b] This property is automatically set to [code]false[/code] after the timer enters the scene tree and starts.
 		</member>
 		<member name="one_shot" type="bool" setter="set_one_shot" getter="is_one_shot" default="false">
 			If [code]true[/code], the timer will stop when reaching 0. If [code]false[/code], it will restart.