Revert "no more coremod :crabrave:"

I'm an idiot. It needs to be a coremod otherwise forge does not add it to the classpath (bruh moment #2)

src/main/java/com/falsepattern/lib/config/ConfigurationManager.java

@@ -8,7 +8,6 @@ import cpw.mods.fml.client.event.ConfigChangedEvent;
 import cpw.mods.fml.common.FMLCommonHandler;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
 
-import java.io.File;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.nio.file.Path;
@@ -26,6 +25,7 @@ import lombok.NoArgsConstructor;
 import lombok.SneakyThrows;
 import lombok.val;
 import lombok.var;
+import net.minecraft.launchwrapper.Launch;
 import net.minecraftforge.common.config.ConfigElement;
 import net.minecraftforge.common.config.Configuration;