Find a way to always have reference documentation updated

Yeah, I thought that the variables accept plain text, but it seems that they only accept URLs. However, I still think we should find a way to handle this, because currently, we have a ton of documentation for different Java versions – 7, 8, 9, 11, 12, 13, 14, etc. Perhaps a policy to only add documentation for the latest current version, but that wouldn't eliminate the need to update the older ones at some point.

_Originally posted by @manumafe98 in https://github.com/exercism/java/issues/2722#issuecomment-1928531785_