Update feature flag note language

doc/administration/audit_event_streaming/graphql_api.md

doc/administration/audit_event_streaming/index.md

doc/administration/backup_restore/backup_gitlab.md

doc/administration/gitaly/configure_gitaly.md

doc/administration/gitaly/index.md

doc/administration/integration/terminal.md

doc/administration/settings/account_and_limit_settings.md

doc/api/graphql/custom_emoji.md

doc/api/group_protected_branches.md

doc/api/group_releases.md

doc/api/groups.md

doc/api/markdown.md

doc/api/pipelines.md

doc/api/product_analytics.md

doc/api/project_import_export.md

doc/ci/components/index.md

doc/ci/review_apps/index.md

doc/ci/yaml/index.md

doc/development/documentation/alpha_beta.md

doc/development/internal_api/internal_api_allowed.md