add link to wikipedia test-driven development

diff --git a/HDL_workflow.mdwn b/HDL_workflow.mdwn
index 41842725c9961b12a65d1ddb40e467f9b9d7d06b..cd7795c6a32b0d2acb5a077e4ff8d7cb8059b00e 100644 (file)
--- a/HDL_workflow.mdwn
+++ b/HDL_workflow.mdwn
@@ -770,6 +770,9 @@ in the xterm window, on which you can base the "commit message".
 
 ## Unit tests
 
+For further reading, see the wikipedia page on
+[Test-driven Development](https://en.wikipedia.org/wiki/Test-driven_development)
+
 This deserves its own special section.  It is extremely important to
 appreciate that without unit tests, python projects are simply unviable.
 Python itself has over 25,000 individual tests.