I've been adding my audiobooks in M4B format to calibre and then joining them with the same books in ePub so they share information. In this way the library is very useful and organized.
It would be easy to create an icon for the M4B format to appear in the sidebar (photo attached). We have a template with the image zero.png in the resources folder --> images --> mimetypes. If I modify that image and create an m4b.png icon, how do I do it so that that icon then appears in the sidebar just like the rest of the file extensions?
