app: update documentation

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/doc.go

@@ -8,12 +8,12 @@ See https://gioui.org for instructions to set up and run Gio programs.
 
 # Windows
 
-Create a new Window by calling NewWindow. On mobile platforms or when Gio
+Create a new [Window] by calling [NewWindow]. On mobile platforms or when Gio
 is embedded in another project, NewWindow merely connects with a previously
 created window.
 
-A Window is run by calling NextEvent in a loop. The most important event is
-FrameEvent that prompts an update of the window contents.
+A Window is run by calling its NextEvent method in a loop. The most important event is
+[FrameEvent] that prompts an update of the window contents.
 
 For example:
 
@@ -30,7 +30,7 @@ For example:
 	}
 
 A program must keep receiving events from the event channel until
-DestroyEvent is received.
+[DestroyEvent] is received.
 
 # Main
 
@@ -55,12 +55,6 @@ For example, to display a blank but otherwise functional window:
 		app.Main()
 	}
 
-# Event queue
-
-A FrameEvent's Queue method returns an event.Queue implementation that distributes
-incoming events to the event handlers declared in the last frame.
-See the gioui.org/io/event package for more information about event handlers.
-
 # Permissions
 
 The packages under gioui.org/app/permission should be imported