Fix error and format issue (#11975)

### What problem does this PR solve?

1. Fix error of book chunking.
2. Fix format issues.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

rag/app/book.py

@@ -166,9 +166,10 @@ def chunk(filename, binary=None, from_page=0, to_page=100000,
         sections = [s.split("@") for s, _ in sections]
         sections = [(pr[0], "@" + pr[1]) if len(pr) == 2 else (pr[0], '') for pr in sections ]
         chunks = naive_merge(
-            sections, kwargs.get(
-                "chunk_token_num", 256), kwargs.get(
-                "delimer", "\n。；！？"))
+            sections,
+            parser_config.get("chunk_token_num", 256),
+            parser_config.get("delimiter", "\n。；！？")
+        )
 
     # is it English
     # is_english(random_choices([t for t, _ in sections], k=218))