add gitignore

.gitignore

@@ -0,0 +1,18 @@
+# Ignore metadata generated by Jekyll
+_site/
+.sass-cache/
+.jekyll-cache/
+.jekyll-metadata
+
+# Ignore folders generated by Bundler
+.bundle/
+vendor/
+
+# Ignore mac files 
+.DS_Store
+
+# temporarily ignore gemfile.lock
+Gemfile.lock
+
+# Ignore objects directory to avoid committing binary files (other than demo files)
+# if you would like to commit your objects to github, delete the line below!