Update .gitlab-ci.yml

.gitlab-ci.yml

@@ -4,9 +4,13 @@ image: ruby:2.7
 pages:
   stage: deploy
   script:
+    - gem install bundler
+    - bundle install
+    - bundle exec jekyll build
     - mkdir .public
     - cp -r * .public
     - mv .public public
+    
   artifacts:
     paths:
       - public