diff --git a/.gitignore b/.gitignore
index 8c962b9..1501c2e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,5 @@ _main.Rmd
 book_assets
 .bundle
 vendor
+*.md
+_main.rds
diff --git a/_bookdown.yml b/_bookdown.yml
index 4dc0c17..a1bb233 100644
--- a/_bookdown.yml
+++ b/_bookdown.yml
@@ -1,3 +1,5 @@
+new_session: yes
+
 rmd_files: [
   "understand.Rmd",
   "visualize.Rmd",