Keep custom configs between modpack updates #704
Description
Would be nice that if a user makes an update to one of the configs in the pack, and they update, if those changes can be kept.
Currently the options.txt is kept fine, but anything in the configs/ folder is not, as the folder is wiped out between modpack updates/reinstalls.
One way thinking about it is to take a note of all files in the config folder on install, and then get a hash of the file, then compare that to the hash of the same file after the pack is updates/reinstalled and if the hash is the same (meaning that since the last version of the pack and the current version, there were no changes to that particular config file), then copy over the old config file if it had changes in it.
If there is a mismatch between config hashes from the old and the new version, then we have to overwrite and not carry over the users changes.
On a side note there was mention in the Discord at some point about a mod called YOSBR (https://www.curseforge.com/minecraft/mc-mods/yosbr) which basically provides a /config/yosbr folder which on boot of the pack will copy those files into the configs folder if it doesn't exist. Would be good to find a modpack which uses this, and then hook into that folder existing with the file the user has replaced and then not delete it.