[css-scroll-snap] Add some recommendations for snapping to :target elements on navigation.

Author: tabatkins

css-scroll-snap/Overview.bs

@@ -841,6 +841,12 @@ Choosing Snap Positions {#choosing}
 
 		Issue: This would prevent space-travel effects. I think we should remove this.
 
+	* If a page is navigated to a fragment that defines a target element
+		(one that would be matched by '':target''),
+		and that element defines some <a>snap positions</a>,
+		the user agent should snap to one of that element's <a>snap positions</a>.
+		The user agent may do this even when the <a>scroll container</a> has ''scroll-snap-type: none''.
+
 	Issue: Does tie-resolution need to be specified? Inertial and semantic scrolls are easy--
 	just choose the next one in the scroll direction--
 	but explicit scrolls don't have a direction.