Document popups being invisible by default

doc/classes/AcceptDialog.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		The default use of [AcceptDialog] is to allow it to only be accepted or closed, with the same result. However, the [signal confirmed] and [signal canceled] signals allow to make the two actions different, and the [method add_button] method allows to add custom buttons and actions.
+		[b]Note:[/b] [AcceptDialog] is invisible by default. To make it visible, call one of the [code]popup_*[/code] methods from [Window] on the node, such as [method Window.popup_centered_clamped].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/ConfirmationDialog.xml

@@ -14,6 +14,7 @@
 		GetCancelButton().Pressed += OnCanceled;
 		[/csharp]
 		[/codeblocks]
+		[b]Note:[/b] [AcceptDialog] is invisible by default. To make it visible, call one of the [code]popup_*[/code] methods from [Window] on the node, such as [method Window.popup_centered_clamped].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/EditorFileDialog.xml

@@ -6,6 +6,7 @@
 	<description>
 		[EditorFileDialog] is an enhanced version of [FileDialog] available only to editor plugins. Additional features include list of favorited/recent files and the ability to see files as thumbnails grid instead of list.
 		Unlike [FileDialog], [EditorFileDialog] does not have a property for using native dialogs. Instead, native dialogs can be enabled globally via the [member EditorSettings.interface/editor/use_native_file_dialogs] editor setting. They are also enabled automatically when running in sandbox (e.g. on macOS).
+		[b]Note:[/b] [EditorFileDialog] is invisible by default. To make it visible, call one of the [code]popup_*[/code] methods from [Window] on the node, such as [method Window.popup_centered_clamped].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/FileDialog.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		[FileDialog] is a preset dialog used to choose files and directories in the filesystem. It supports filter masks. [FileDialog] automatically sets its window title according to the [member file_mode]. If you want to use a custom title, disable this by setting [member mode_overrides_title] to [code]false[/code].
+		[b]Note:[/b] [FileDialog] is invisible by default. To make it visible, call one of the [code]popup_*[/code] methods from [Window] on the node, such as [method Window.popup_centered_clamped].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/Popup.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		[Popup] is a base class for contextual windows and panels with fixed position. It's a modal by default (see [member Window.popup_window]) and provides methods for implementing custom popup behavior.
+		[b]Note:[/b] [Popup] is invisible by default. To make it visible, call one of the [code]popup_*[/code] methods from [Window] on the node, such as [method Window.popup_centered_clamped].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/PopupMenu.xml

@@ -8,6 +8,7 @@
 		The size of a [PopupMenu] can be limited by using [member Window.max_size]. If the height of the list of items is larger than the maximum height of the [PopupMenu], a [ScrollContainer] within the popup will allow the user to scroll the contents. If no maximum size is set, or if it is set to [code]0[/code], the [PopupMenu] height will be limited by its parent rect.
 		All [code]set_*[/code] methods allow negative item indices, i.e. [code]-1[/code] to access the last item, [code]-2[/code] to select the second-to-last item, and so on.
 		[b]Incremental search:[/b] Like [ItemList] and [Tree], [PopupMenu] supports searching within the list while the control is focused. Press a key that matches the first letter of an item's name to select the first item starting with the given letter. After that point, there are two ways to perform incremental search: 1) Press the same key again before the timeout duration to select the next item starting with the same letter. 2) Press letter keys that match the rest of the word before the timeout duration to match to select the item in question directly. Both of these actions will be reset to the beginning of the list if the timeout duration has passed since the last keystroke was registered. You can adjust the timeout duration by changing [member ProjectSettings.gui/timers/incremental_search_max_interval_msec].
+		[b]Note:[/b] [PopupMenu] is invisible by default. To make it visible, call one of the [code]popup_*[/code] methods from [Window] on the node, such as [method Window.popup_centered_clamped].
 		[b]Note:[/b] The ID values used for items are limited to 32 bits, not full 64 bits of [int]. This has a range of [code]-2^32[/code] to [code]2^32 - 1[/code], i.e. [code]-2147483648[/code] to [code]2147483647[/code].
 	</description>
 	<tutorials>