TODO: Use `page_description` added in Wagtail 3.0

We should provide useful page descriptions / help text in the Wagtail admin https://docs.wagtail.org/en/stable/topics/pages.html#page-descriptions

Read the Wagtail page descriptions documentation linked in the issue first, then locate the CodeRed CMS page models or admin configuration that define the relevant Wagtail pages. Identify which pages lack useful descriptions or help text, and consider the work complete when the affected admin fields provide clear descriptions consistent with the linked guidance.

Written by the indexing model from the issue text.