Release 0.40.0
Changes:
- Add support for Text-Hörbücher
- Loosen some of the validation restrictions
- normalize Unicode text so that combining diacritic marks are merged with the associated characters. The font Verdana that we use doesn't have support for all these diacritic marks
See https://github.com/sbsdev/catalog/milestone/2?closed=1
Full Changelog: 0.37.0...0.40.0