Address PR review comments

book-example/src/cli/build.md

@@ -36,5 +36,4 @@ not specified it will default to the value of the `build.build-dir` key in
 -------------------
 
 ***Note:*** *The build command copies all files (excluding files with `.md` extension) from the source directory
-into the build directory. If the build directory is under the source directory it is not copied as this would
-result in a recursive copy until your disk is full.*
+into the build directory.*

src/utils/fs.rs

@@ -115,7 +115,7 @@ pub fn copy_files_except_ext(
         let entry = entry?;
         let metadata = entry.metadata()?;
 
-        // If the entry is a dir and the recursive option is enabled , call itself
+        // If the entry is a dir and the recursive option is enabled, call itself
         if metadata.is_dir() && recursive {
             if entry.path() == to.to_path_buf() {
                 continue;