Processing book metadata for NNELS

Steps for cataloguers to clean up and process MARC record sets:

1. Update the MARC record set, follow the steps here: https://bclc.wiki.libraries.coop/doku.php?id=public:nnels:cataloguing:update-marc-records
2. Export your MARC record set as XML, follow the steps here: https://bclc.wiki.libraries.coop/doku.php?id=nnels:documentation:content:publishing:marc21-marcxml
3. Upload the MARC XML set to Drupal, follow the steps here: https://bclc.wiki.libraries.coop/doku.php?id=nnels:documentation:content:publishing:upload-marcxml
4. Parse the MARC XML set in Drupal, follow the steps here: https://bclc.wiki.libraries.coop/doku.php?id=nnels:documentation:content:publishing:parse-marcxml
5. Double-check that NNELS genre terms have been added in the genre harmonized public field in Drupal