Weld: Preserve LICENSE files

[Tschipcraft]

Currently, weld removes all files that are not directly used. However, it would be nice to make an exception for LICENSE files in the root folder. The ID or namespace of the corresponding data pack could be added as a suffix to allow preservation of all LICENSE files, e.g. LICENSE_ttc.
This is especially important on smithed.net, since by default all packs are welded before download.

[rx-dev]

Sorry this was missed, this is a really good point. i'll think about how i can do that