Put event-resource back in to try to fix codeberg gitea issue

I am having trouble with merge conflicts trying to merge the actions changes into the Codeberg repo, see https://codeberg.org/valueflows/pages/pulls/22 (and /21). After some investigation, it seems it is likely a Codeberg or Gitea bug. To try to get my most recent Action changes in now though, I'm trying it again with the page (event-resource.md) that was removed, put back in. This will presumably remove the menu change that affects all pages, and keep the changes to just the 2 pages. It will also further test to see if I am right on the problem.