Make all of the container pages use a "template" system of some kind

Currently and for the foreseeable future, all pages about our container presets use the same format, same layout, same items, etc... with just a couple different changes for stuff like GHCR URL, Dockerfile, file structure, you get the idea. To prevent having to layout everything again each time, having a template Astro component to extract that stuff into would reduce burden on needing to upkeep all these different yet similar pages together.