Annotate the models

app/models/appearance.rb

app/models/application_setting.rb

app/models/audit_event.rb

app/models/broadcast_message.rb

app/models/ci/build.rb

app/models/ci/commit.rb

app/models/ci/runner.rb

app/models/ci/trigger.rb

app/models/ci/variable.rb

app/models/commit_status.rb

app/models/deploy_key.rb

app/models/email.rb

app/models/event.rb

app/models/generic_commit_status.rb

app/models/group.rb

app/models/hooks/project_hook.rb

app/models/hooks/service_hook.rb

app/models/hooks/system_hook.rb

app/models/hooks/web_hook.rb

app/models/identity.rb