Add books and manga to about page

src/lib/books/books.ts

@@ -0,0 +1,24 @@
+import type { Book } from '#lib/content';
+
+const coverBaseUrl = 'https://covers.openlibrary.org/b/isbn';
+const bookPageBaseUrl = 'https://openlibrary.org/isbn';
+
+function cleanIsbn(isbn: string): string {
+	return isbn.replace(/[^0-9X]/gi, '');
+}
+
+export function bookCover(book: Book): string | null {
+	return book.isbn ? `${coverBaseUrl}/${cleanIsbn(book.isbn)}-L.jpg?default=false` : null;
+}
+
+export function bookLink(book: Book): string | null {
+	if (book.url) return book.url;
+	return book.isbn ? `${bookPageBaseUrl}/${cleanIsbn(book.isbn)}` : null;
+}
+
+export function sortBooks(books: Book[]): Book[] {
+	return [...books].sort((first, second) => {
+		const readingOrder = Number(second.status === 'reading') - Number(first.status === 'reading');
+		return readingOrder || (second.rating ?? 0) - (first.rating ?? 0);
+	});
+}