fix: begin to create development instruction

Author: lwasser

CONTRIBUTING.md

@@ -3,3 +3,9 @@
 To work on the template locally, you can call the copier template using:
 
 `copier copy /path/to/your/template destination-folder`
+
+## Run the tests
+
+You can use Hatch to run all of the tests for the template:
+
+`hatch run test:run`