aquaproj/aqua v0.4.0-1 on GitHub

Feature

#162 #164 Support the registry type official

registries:
- type: official
  ref: v0.1.1-0

This is equivalent to the following definition.

registries:
- name: official
  type: github_content
  repo_owner: suzuki-shunsuke
  repo_name: aqua-registry
  ref: v0.1.1-0
  path: registry.yaml

#160 Add the slide to README