Support geyser standalone

Hey; I saw that on the documentation site the itzg container has support for a lot of server types.
Would it be possible to add support out the box for [geyser-standalone](https://geysermc.org/wiki/geyser/setup?host=self&platform=standalone)?

Since server types like Limbo are supported, I dont think it would be a stretch to include Geyser Standalone.

_Originally posted by @SquatchHunter in https://github.com/itzg/docker-minecraft-server/discussions/3639_

Review the existing Limbo server-type support and the linked Geyser Standalone setup documentation first. Add Geyser Standalone in the same support path, then verify that the container recognizes the new server type and that the documentation site lists it.

Written by the indexing model from the issue text.