Additional document attributes

[anermina]

Several non-existing document attributes have been added in #6 just to keep the information visible:

• link_{i} for EWIS-IF AP242_Electrical_Harness_Tutorial_XML
  
• status-note for EWIS-IF AP242_Electrical_Harness_Tutorial_XML
  
• date and date_2 for CAx-IF test_suite_53j_v1 for the period defined on the cover page
  
• round for CAx-IF test_suite_53j_v1
  
• contact-type_{i} for CAx-IF rec_prac_unicode_strings_v1_20230425 and CAE-IF HandbookVolume2_V1.1_CAE-IF
  

[opoudjis]

The entire point of metanorma/metanorma-generic#77 is to attempt to create a flavour without ANY code, relying exclusively on configuration. This is a proof of concept.

If we need to provide code to encode these attributes, then we cannot create the flavour based purely on configuration, and the proof of concept ipso facto fails.