Update README.md

Fix example code.
Minor edits to text.

README.md

@@ -222,16 +222,16 @@ A TwoStateToolbarAction displays one of two icons based on the stored state. It
 to a regular ToolbarAction except that the icon and state are toggled each time the toolbar
 action is activated. The current (new) state is passed to the `onActivated` function.
 
-One potential use of this toolbar action include displaying the MediaPlayIcon when a media 
+One potential use of this toolbar action is displaying the MediaPlayIcon when a media 
 file is not being played, and the MediaPauseIcon or MediaStopIcon when a media file is 
 being played. A second use may be seen in an application where a left or right panel is 
-di8splayed or not. For example, show the left panel open icon when the left panel is 
+displayed or not. For example, show the left panel open icon when the left panel is 
 closed, and the left panel close icon when the panel is open.
 
 
 ```go
 action := NewTwoStateToolBar(theme.MediaPlayIcon(), 
-    theme.MediaPauseIcon, 
+    theme.MediaPauseIcon(), 
     func(on bool) {
         // Do something with state. For example, if on is true, start playback.
     })