Add default variables with example values

defaults/main.yml

@@ -0,0 +1,10 @@
+---
+site_name: "example-site"
+deploy_dirs: 
+  - "/srv/{{ site_name }}/"
+  # - "/srv/{{ site_name }}-staging/"
+deploy_user: "jekyll"
+deploy_group: "jekyll"
+
+ruby_version: "2.7"
+bundler_version: "2.1.4"