Release v1.12.0

Release v1.12.0

release-check: OK beb48c6

Changelog

Added

• Public page options, so hosts no longer override maintenance/page.html.twig for them: page.illustration (image
  above the badge, WebP first) and page.countdown (a live countdown to the scheduled end, the script nonced from
  page.csp_nonce_attribute; without it the page still ships no JavaScript).
• Panel options: web_ui.show_preview_link (a link to the public page preview under the status) and
  web_ui.form_theme (form theme of the section forms, e.g. UiKit's nowo_ui_layout). New key
  panel.status.preview in the 7 locales.

Full Changelog: v1.11.0...v1.12.0