Improve test cases doc

Author: wlsf82

docs/TestCases.md

@@ -1,8 +1,10 @@
 # Test cases
 
-Below is a list of test cases that could be covered by automated scripts for the **EngageSphere** application.
+Below is a list of test cases currently covered by automated scripts for the **EngageSphere** application.
 
-The tests should cover both the API and Graphical User Interface (GUI.)
+The tests cover both the API and Graphical User Interface (GUI.)
+
+> The GUI tests cover integrated frontend tests, accessibility (a11y) tests, and component tests.
 
 ## API