Document that `Input.is_action_*` should not be used during input-handling

In most cases `InputEvent.is_action*` is more appropriate during input-handling.

doc/classes/Input.xml

@@ -198,6 +198,7 @@
 				If [param exact_match] is [code]false[/code], it ignores additional input modifiers for [InputEventKey] and [InputEventMouseButton] events, and the direction for [InputEventJoypadMotion] events.
 				[b]Note:[/b] Returning [code]true[/code] does not imply that the action is [i]still[/i] pressed. An action can be pressed and released again rapidly, and [code]true[/code] will still be returned so as not to miss input.
 				[b]Note:[/b] Due to keyboard ghosting, [method is_action_just_pressed] may return [code]false[/code] even if one of the action's keys is pressed. See [url=$DOCS_URL/tutorials/inputs/input_examples.html#keyboard-events]Input examples[/url] in the documentation for more information.
+				[b]Note:[/b] During input handling (e.g. [method Node._input]), use [method InputEvent.is_action_pressed] instead to query the action state of the current event.
 			</description>
 		</method>
 		<method name="is_action_just_released" qualifiers="const">
@@ -208,6 +209,7 @@
 				Returns [code]true[/code] when the user [i]stops[/i] pressing the action event in the current frame or physics tick. It will only return [code]true[/code] on the frame or tick that the user releases the button.
 				[b]Note:[/b] Returning [code]true[/code] does not imply that the action is [i]still[/i] not pressed. An action can be released and pressed again rapidly, and [code]true[/code] will still be returned so as not to miss input.
 				If [param exact_match] is [code]false[/code], it ignores additional input modifiers for [InputEventKey] and [InputEventMouseButton] events, and the direction for [InputEventJoypadMotion] events.
+				[b]Note:[/b] During input handling (e.g. [method Node._input]), use [method InputEvent.is_action_released] instead to query the action state of the current event.
 			</description>
 		</method>
 		<method name="is_action_pressed" qualifiers="const">