This summer, we're celebrating the individual books that readers have fallen in love with. We've sought submissions from authors to artists, musicians to booksellers, and from you, Penguin Classics readers. Each book you've shared tells a story of its own, through its cracked spine, dog-eared pages, scribbled margins or its missing cover. And because the most beautiful books are the ones that have been well-read, we’d love to see yours. Look out for the posters across the UK and share your…