Move requirements for PiP window visibility and closing

See #191

index.bs

@@ -209,6 +209,8 @@ the user agent MUST run the following steps:
 8. Set {{pictureInPictureElement}} to |video|.
 9. Let <dfn>Picture-in-Picture window</dfn> be a new instance of
     {{PictureInPictureWindow}} associated with {{pictureInPictureElement}}.
+10. When the Picture-in-Picture window is opened it MUST be visible, even when
+    the <a>Document</a> is not in focus or hidden.
 10. Append <a>relevant settings object</a>'s <a>origin</a> to
     <a>initiators of active Picture-in-Picture sessions</a>.
 11. <a>Queue a task</a> to <a>fire an event</a> named
@@ -237,6 +239,9 @@ It is also RECOMMENDED that the Picture-in-Picture window has a maximum and
 minimum size. For example, it could be restricted to be between a quarter and
 a half of one dimension of the screen.
 
+The user agent SHOULD provide a way for users to manually close the
+Picture-in-Picture window.
+
 ## Exit Picture-in-Picture ## {#exit-pip}
 
 When the <dfn>exit Picture-in-Picture algorithm</dfn> is invoked,
@@ -306,11 +311,6 @@ available controls on the Picture-in-Picture window.
 
 ## Interaction with Page Visibility ## {#page-visibility}
 
-When {{pictureInPictureElement}} is set, the Picture-in-Picture window MUST
-be visible, even when the <a>Document</a> is not in focus or hidden. The user
-agent SHOULD provide a way for users to manually close the Picture-in-Picture
-window.
-
 The Picture-in-Picture window visibility MUST NOT be taken into account by the
 user agent to determine if the <a>system visibility state</a> of a 
 <a for="/">traversable navigable</a> has changed.