add bookdown example
diff --git a/docs/bookdown_example/_bookdown.yml b/docs/bookdown_example/_bookdown.yml
new file mode 100644
index 0000000..a189c96
--- /dev/null
+++ b/docs/bookdown_example/_bookdown.yml
@@ -0,0 +1,6 @@
+book_filename: "bookdown_example"
+delete_merged_file: true
+new_session: true
+language:
+  ui:
+    chapter_name: "Chapter "