README.md in lolp-0.3.0 vs README.md in lolp-0.4.0

@@ -37,9 +37,18 @@
 Lolp.delete_project('jungly-naha-2778')
 Lolp.create_custom_domain('jungly-naha-2778.lolipop.ohr','example.com')
 Lolp.delete_custom_domain('jungly-naha-2778.lolipop.ohr','example.com')
 ```
 
+### Certificate
+
+```ruby
+# get certificates infomation
+Lolp.get_certificate('agile-kitsuki-0978.lolipop.io')
+# create certificates
+Lolp.create_certificate('agile-kitsuki-0978.lolipop.io')
+```
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).