add test documentation

Readme.md

@@ -23,6 +23,14 @@ Note, be sure to use python3.11 with this application
 
 > python -m app.debug.py
 
+Run tests
+
+> pytest
+
+Run specific tests
+
+> pytest app\test\test_volunteer.py
+
 ## Credit
 
 FastAPI project generated using https://github.com/rafsaf/minimal-fastapi-postgres-template