Add Ternary for Displaying Placeholder If Book Lacks Cover

[livoszlak]

Sometimes the results from the API don't contain a cover image for the book. This means the BookItem just has a broken image link and displays the alt text. I would like a placeholder icon in place of the non-existent cover img. Maybe the ImageNotSupported icon from MUI could work. If you want to work in another ternary for the icon to have a "Placeholder icon: cover for [book.title] not found" as alt text, that works.

[Sarveshk76]

Hi @livoszlak, I would like to work on this

[livoszlak]

@Sarveshk76 Absolutely! I'll assign you right away. Thank you! 🌷