Keep LastEdited dates in demo fresh

[chillu]

Overview

As a content author reviewing the demo, I can see recently edited pages in order to get a good feel for what an active CMS environment would look like

Acceptance Criteria

• I can see entries in the report for "pages edited in the last two weeks"

Notes

• Split out from Site admin: Reporting
• This could be done with a startup script on the Docker container. Can't be in the Dockerfile since that container gets built once, and then reused over time for demos
• Serge suggests we do that as a Flushable implementation so that dev/build does that on deploy.