Local folder link support

[Filiflo]

This would be helpful to quickly try out a work in progress pack without pushing it to a server every time

[Filiflo]

It seems like it just doesn't do absolute file paths ~/Documents/PackHERE/pack.toml didnt work, but
./PackHERE/pack.toml worked fine when placed into the instances .minecraft folder.

I think absolute paths should be possible but it might not for security reasons of the java instance or my package manager.

I will still keep this open for now, though it is possible to work on the pack by placing it in the instance itself