more screenshots (#278)

ios12/GroupedNotifications/README.md

@@ -5,6 +5,8 @@ This sample app demonstrates how to use the User Notifications framework
 to group notifications by their thread identifiers, a new feature 
 introduced in iOS 12 to make it easier for users to work with notifications.
 
+![Example grouped and expanded notifications](Screenshots/all-sml.png)
+
 Usage
 -------
 

ios12/MarsHabitatCoreMLTimer/README.md

@@ -7,6 +7,8 @@ sample to demonstrate the performance benefit of using iOS 12's Core ML
 batch prediction API instead of looping over the standard Core ML
 prediction API.
 
+![batch processing timer](Screenshots/complete-sml.png)
+
 License
 -------
 Code is released under the MIT license

ios12/RedGreenNotifications/README.md

@@ -19,6 +19,7 @@ This sample demonstrates how to:
 - Set up an in-app notification management screen to which iOS can directly 
 link.
 
+![Provisional nortifications examples](Screenshots/all-sml.png)
 
 Usage
 -------

ios12/XamarinNL/README.md

@@ -5,11 +5,12 @@ This app demonstrates how to use Apple's Natural Language framework
 to recognize languages, tokenize text into words and sentences, and
 tag named entities and parts of speech in a body of text.
 
+![Examples of natural language parsing](Screenshots/all-sml.png)
+
 License
 -------
 Code is released under the MIT license
 
 Author
 -------
-Brad Umbaugh
-
+Brad Umbaugh