Add images for sort commands in UG

docs/UserGuide.md

@@ -254,6 +254,17 @@ Format: `sort n/`
 Example:
 * `sort n/` sorts all persons in PressPlanner in ascending order by the lexicographical (alphabetical) ordering of their names.
 
+Before sorting:
+(Aaron Tan and Barry Allen are recent additions to the template data and are currently at the end of the list)
+![before sorting people](images/beforeSortingPeople.png)
+
+After sorting:
+(Both Aaron Tan and Barry Allen moved up the list and are now in order with respect to ascending alphabetical ordering of their names)
+![after sorting people](images/afterSortingPeople.png)
+
+Success message shown:
+`sorted all persons by name`
+
 ### [3.1.8. Clearing All Persons : `clear`](#31-managing-contacts)
 
 Clears all entries from the address book.
@@ -411,6 +422,17 @@ Format: `sort -a d/`
 Example:
 * `sort -a d/` sorts all articles in PressPlanner in descending order by their date and time.
 
+Before sorting:
+(The first and second articles are in ascending order by date)
+![before sorting articles](images/beforeSortingArticles.png)
+
+After sorting:
+(The articles are now in descending order by date)
+![after sorting articles](images/afterSortingArticles.png)
+
+Success message shown:
+`sorted all articles by date`
+
 ### [3.2.10. Opening a Webpage for an Article](#32-managing-articles)
 
 * By clicking the `Link` button of your article that is highlighted in yellow box in the picture below, you can open up the webpage for your article that is added when you added the article.