Avoid some gtk-doc warnings

docs/reference/gdk/gdk3-sections.txt

@@ -61,7 +61,6 @@ GdkStatus
 GDKVAR
 gdk_axis_use_get_type
 gdk_byte_order_get_type
-gdk_cap_style_get_type
 gdk_crossing_mode_get_type
 gdk_cursor_type_get_type
 gdk_drag_action_get_type
@@ -77,17 +76,14 @@ gdk_input_mode_get_type
 gdk_input_source_get_type
 gdk_modifier_type_get_type
 gdk_notify_type_get_type
-gdk_overlap_type_get_type
 gdk_property_state_get_type
 gdk_prop_mode_get_type
 gdk_scroll_direction_get_type
 gdk_setting_action_get_type
 gdk_status_get_type
-gdk_subwindow_mode_get_type
 gdk_visibility_state_get_type
 gdk_visual_type_get_type
 gdk_window_attributes_type_get_type
-gdk_window_class_get_type
 gdk_window_edge_get_type
 gdk_window_hints_get_type
 gdk_window_state_get_type
@@ -309,7 +305,6 @@ GDK_VISUAL_GET_CLASS
 
 <SUBSECTION Private>
 GdkVisualClass
-GdkVisualPrivate
 gdk_visual_get_type
 </SECTION>
 
@@ -498,7 +493,6 @@ GDK_TYPE_FILTER_RETURN
 GDK_TYPE_GRAVITY
 GDK_TYPE_MODIFIER_TYPE
 GDK_TYPE_WINDOW_ATTRIBUTES_TYPE
-GDK_TYPE_WINDOW_CLASS
 GDK_TYPE_WINDOW_EDGE
 GDK_TYPE_WINDOW_HINTS
 GDK_TYPE_WINDOW_TYPE
@@ -509,7 +503,6 @@ GDK_TYPE_WM_FUNCTION
 <SUBSECTION Private>
 gdk_window_get_type
 gdk_window_window_class_get_type
-GdkWindowObject
 GdkWindowClass
 GdkWindowImpl
 GdkWindowImplClass
@@ -555,17 +548,8 @@ GdkAtom
 GDK_ATOM_TO_POINTER
 GDK_POINTER_TO_ATOM
 GDK_NONE
-gdk_text_property_to_text_list
-gdk_text_property_to_text_list_for_display
-gdk_free_text_list
-gdk_text_property_to_utf8_list
 gdk_text_property_to_utf8_list_for_display
-gdk_string_to_compound_text
-gdk_string_to_compound_text_for_display
-gdk_free_compound_text
 gdk_utf8_to_string_target
-gdk_utf8_to_compound_text
-gdk_utf8_to_compound_text_for_display
 gdk_atom_intern
 gdk_atom_intern_static_string
 gdk_atom_name
@@ -631,10 +615,6 @@ gdk_threads_add_timeout
 gdk_threads_add_timeout_full
 gdk_threads_add_timeout_seconds
 gdk_threads_add_timeout_seconds_full
-
-<SUBSECTION Private>
-gdk_threads_lock
-gdk_threads_unlock
 </SECTION>
 
 <SECTION>
@@ -691,8 +671,6 @@ GdkDevice
 GdkDeviceType
 GdkInputSource
 GdkInputMode
-GdkDeviceKey
-GdkDeviceAxis
 GdkAxisUse
 GdkGrabOwnership
 gdk_disable_multidevice
@@ -753,9 +731,7 @@ GDK_TYPE_DEVICE
 
 <SUBSECTION Private>
 GdkDeviceClass
-GdkDevicePrivate
 GdkDeviceManagerClass
-GdkDeviceManagerPrivate
 gdk_device_get_type
 gdk_device_manager_get_type
 gdk_device_type_get_type
@@ -899,15 +875,12 @@ gdk_cursor_get_type
 gdk_drag_get_selection
 gdk_drag_abort
 gdk_drop_reply
-gdk_drag_context_new
 gdk_drag_drop
-gdk_drag_find_window
 gdk_drag_find_window_for_screen
 gdk_drag_context_get_source_window
 gdk_drag_begin
 gdk_drag_motion
 gdk_drop_finish
-gdk_drag_get_protocol
 gdk_drag_get_protocol_for_display
 GdkDragProtocol
 GdkDragContext
@@ -1016,7 +989,6 @@ GDK_IS_APP_LAUNCH_CONTEXT
 GDK_IS_APP_LAUNCH_CONTEXT_CLASS
 GDK_TYPE_APP_LAUNCH_CONTEXT
 GdkAppLaunchContextClass
-GdkAppLaunchContextPrivate
 <SUBSECTION Private>
 gdk_app_launch_context_get_type
 </SECTION>