Add example of config as well

src/main/java/dev/hytalemodding/config/ExampleConfig.java

@@ -0,0 +1,25 @@
+package dev.hytalemodding.config;
+
+import com.hypixel.hytale.codec.Codec;
+import com.hypixel.hytale.codec.KeyedCodec;
+import com.hypixel.hytale.codec.builder.BuilderCodec;
+
+public class ExampleConfig {
+
+    public static final BuilderCodec<ExampleConfig> CODEC = BuilderCodec.builder(ExampleConfig.class, ExampleConfig::new)
+            .append(
+                new KeyedCodec<>("EnableWelcomeMessage", Codec.BOOLEAN),
+                (exConfig, aBoolean, extraInfo) -> exConfig.enabledWelcomeMessage = aBoolean,
+                (exConfig, extraInfo) -> exConfig.enabledWelcomeMessage
+            )
+            .add()
+            .build();
+
+    private boolean enabledWelcomeMessage;
+
+    private ExampleConfig() {}
+
+    public boolean isEnabledWelcomeMessage() {
+        return enabledWelcomeMessage;
+    }
+}