Update README, mention defaultconfigs

README.md

@@ -23,6 +23,8 @@ The modpack is currently only available as a **self-updating** PolyMC / MultiMC
 - On first launch, [packwiz] will download all mods and other modpack files.  
   On future launches, it will automatically check for updates and apply them.
 
+When updating the modpack, not all changes might be applied, because some settings are stored *per world*, which won't be overridden by the update process. If you're just playing multiplayer, this won't matter to you. If you're playing singleplayer however, you might want to copy the contents of the `defaultconfigs` folder into your world's `serverconfig` folder every now and then.
+
 [PolyMC]:  https://polymc.org/
 [MultiMC]: https://multimc.org/
 [packwiz]: https://github.com/packwiz/packwiz
@@ -40,6 +42,9 @@ wget https://maven.minecraftforge.net/net/minecraftforge/forge/1.18.2-40.1.68/fo
 
 # Download modpack files. Also run this to update.
 java -jar packwiz-installer-bootstrap.jar -g -s server https://meowface.org/copygirl/heck/pack.toml
+# Changes made to files in `defaultconfigs` during updates are not applied to existing worlds.
+# Therefore it is advised to copy them over by running the following command.
+cp defaultconfigs/* $WORLD_LOCATION/serverconfig/
 
 # Download Minecraft and Forge files.
 java -jar forge-1.18.2-40.1.68-installer.jar --installServer