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[thebioengineer]

Add to vt_use_req(), vt_use_test_case(), and vt_use_test_code() the ability to automatically be added to validation.yml.

Will need default add methodology too: group reqs, test case and test code?

To avoid having to do:

vt_use_req("New_requirement_100")
vt_add_file_to_config("New_requirement_100.md", after = "New_requirement_099.md")

More like:

vt_use_req("New_requirement_100", add_after = "New_requirement_099.md")