create Unit and Property Tests Overview page.

Unit-and-Property-Tests-Overview.md

@@ -0,0 +1,14 @@
+Within TestCentre, you will see a collection of unit and property tests. Each type of test uses their own testing library. For unit tests, I have used xUnit and I have used FsCheck for the property tests. If you are unfamiliar with either of these libraries, please use the following links;
+
+- [xUnit](https://xunit.net/)
+- [FsCheck](https://fscheck.github.io/FsCheck/)
+
+It is worth pointing out TestCentre uses xUnit's Test Runner for Visual Studio. This means you can use Visual Studio's Test Explorer -- which shows you the project's (unit and property) tests with a graphical user interface (G.U.I.). If you are unsure what that is, below is a screenshot of what it looks like.
+
+IMAGE OF VISUAL STUDIO TEST EXPLORE.
+
+As you can see, it is a good way to determine what tests are passing and failing. On top of that, it highlights how the tests are organised within TestCentre.
+
+For more information about Visual Studio's Test Explorer, use the following link;
+
+- [Visual Studio's Test Explorer](https://docs.microsoft.com/en-us/visualstudio/test/run-unit-tests-with-test-explorer?view=vs-2019)