Rename CI YAML index file

app/assets/javascripts/editor/schema/ci.json

...cripts/environments/components/stop_environment_modal.vue

...javascripts/environments/environment_details/constants.js

app/assets/javascripts/releases/components/app_index.vue

app/helpers/ci/pipeline_editor_helper.rb

app/models/concerns/ci/has_completion_reason.rb

app/serializers/build_details_entity.rb

app/views/projects/blob/viewers/_gitlab_ci_yml.html.haml

...ws/projects/blob/viewers/_gitlab_ci_yml_loading.html.haml

doc/administration/cicd/compute_minutes.md

doc/administration/cicd/job_artifacts.md

doc/administration/dedicated/hosted_runners.md

doc/administration/instance_limits.md

doc/administration/settings/continuous_integration.md

doc/administration/settings/instance_template_repository.md

doc/administration/settings/usage_statistics.md

doc/api/commits.md

doc/api/job_artifacts.md

doc/api/jobs.md

doc/api/lint.md