[css-round-display] Modify notes related to shape media feature

Author: jihyerish

css-round-display/Overview.bs

@@ -186,10 +186,22 @@ It accepts the following values:
 		</figcaption>
 	</div>
 </div>
-
-<p class="note">Note: There are cases when the UA may know the shape even in the absence of OS APIs. For example, when rendering to PDF, the shape is known to be a rectangle, so 'shape: rect' evaluates to ''true'' while ''shape: round'' to ''false''
+<p class="note">
+Note: So far, the only standard APIs of Operating System which exposes 
+information about the display's shape is 
+<a href="http://developer.android.com/intl/es/reference/android/content/res/Configuration.html#isScreenRound%28%29">''isScreenRound()'' API</a>
+in Android. 
+<a href="http://developer.android.com/intl/es/reference/android/content/res/Configuration.html#isScreenRound%28%29">''isScreenRound()'' API</a>
+ returns a boolean that says round or not.<br>
+Refered the semantics of this API, when isScreenRound() returns ''true'', ''shape: round'' should evaluate
+ to ''true''
+and ''shape: rect'' should evaluate to ''false'' when isScreenRound() returns ''false''.<br>
+'shape' is dealing with 2 shapes, but it can be extended if there are the needs about
+configuring other shapes from the developers.
 </p>
-<p class="note">Note: For other shapes, such as polygons, we need to extend the media features with additional parameters. The current features have limitations to support the diversity beyond round shapes. How can we express star-shaped polygons? (e.g. SVG syntax, etc.) Of course, there is a trade-off between simplicity and expressiveness.
+<p class="note">Note: There are cases when the UA may know the shape even in the absence of OS APIs. 
+For example, when rendering to PDF, the shape is known to be a rectangle, so 'shape: rect' evaluates to
+ ''true'' while ''shape: round'' to ''false''
 </p>
 
 Extending the @viewport rule {#extending-viewport-rule}