Update to 1.20

Now uses split-sourceset's

src/main/java/com/example/ExampleMod.java

@@ -0,0 +1,22 @@
+package com.example;
+
+import net.fabricmc.api.ModInitializer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ExampleMod implements ModInitializer {
+    // This logger is used to write text to the console and the log file.
+    // It is considered best practice to use your mod id as the logger's name.
+    // That way, it's clear which mod wrote info, warnings, and errors.
+    public static final Logger LOGGER = LoggerFactory.getLogger("modid");
+
+    @Override
+    public void onInitialize() {
+        // This code runs as soon as Minecraft is in a mod-load-ready state.
+        // However, some things (like resources) may still be uninitialized.
+        // Proceed with mild caution.
+
+        LOGGER.info("Hello Fabric world!");
+    }
+}