Derive Clone and Debug for Chapter and Book

src/book/book.rs

@@ -4,6 +4,7 @@ use book::chapter::Chapter;
 
 /// The `Book` struct contains the metadata and chapters for one language of the book.
 /// Multiple `Book` structs are combined in the `MDBook` struct to support multi-language books.
+#[derive(Debug, Clone)]
 pub struct Book {
     metadata: BookMetadata,
 

src/book/chapter.rs

@@ -2,6 +2,7 @@ use std::path;
 
 /// The Chapter struct holds the title of the chapter as written in the SUMMARY.md file,
 /// the location of the markdown file containing the content and eventually sub-chapters
+#[derive(Debug, Clone)]
 pub struct Chapter {
     title: String,
     file: path::PathBuf,