Add feature parity with datapack handling

[MrScopi]

Enhancement Type

Improve an existing feature

Describe the enhancement

For datapacks, add the functionality to map a "datapacks" directory that would be automatically imported to the $WORLD/datapacks folder.

Essentially, add parity between datapacks and the current mods/plugins functionality.

This is currently achieved by manually symlinking the folder, but it would be great to have the same functionality for simplicity's sake.

Thanks for a great container!