Merge topic 'doc-create_test_sourcelist'

2c646641ec Help: Document create_test_sourcelist source path convention
c21f0eb30b Help: Modernize create_test_sourcelist documentation

Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Ben Boeckel <ben.boeckel@kitware.com>
Merge-request: !9281