Docs for configuring/running Pelican via Docker are in the wrong spot

[jhiemstrawisc]

Pelican documentation for configuring/operating servers out of Docker is located under the Installing Pelican section of our documentation:
https://docs.pelicanplatform.org/install/docker

This is confusing and not the place someone wanting to configure a Docker container for Pelican would think to look.

I propose we keep that install/docker webpage, but instead of talking about configuration we should only talk about how to get our containers, how our container naming convention works, and how to pick the correct container for the user's application (e.g. cache v origin, pelican v osdf). These are the same types of documentation we provide in the install section for people getting a Pelican executable/package.