* added simple segmentation tei generator

* added test_should_add_line_feeds

* add lb element before line feeds

* added get_training_tei_xml_for_model_data_iterable

* replaced get_training_tei_children_for_layout_line

* refactored iter_tei_child_for_model_data_iterable

* refactored get_training_tei_xml_for_layout_document

* added training documentation

* added dummy generate training data cli

* moved to training.cli package

* generate output path

* convert to layout document

* generated segmentation tei xml

* removed model arg

* added get_parsed_layout_document to Parser

* added get_layout_document

* write raw training data

* added support for glob file patterns

* extracted generate_training_data_for_source_filename

* extracted generate_training_data_for_layout_document

* pass xml tag name as positional argument

* extracted _get_training_tei_xml_for_children