Add SettingsChangedEvent

src/main/java/com/replaymod/core/SettingsRegistry.java

@@ -1,7 +1,9 @@
 package com.replaymod.core;
 
+import com.replaymod.core.events.SettingsChangedEvent;
 import net.minecraft.client.resources.I18n;
 import net.minecraftforge.common.config.Configuration;
+import net.minecraftforge.fml.common.FMLCommonHandler;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -81,6 +83,7 @@ public class SettingsRegistry {
             throw new IllegalArgumentException("Default type " + key.getDefault().getClass() + " not supported.");
         }
         settings.put(key, value);
+        FMLCommonHandler.instance().bus().post(new SettingsChangedEvent(this, key));
     }
 
     public void save() {

src/main/java/com/replaymod/core/events/SettingsChangedEvent.java

@@ -0,0 +1,15 @@
+package com.replaymod.core.events;
+
+import com.replaymod.core.SettingsRegistry;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import net.minecraftforge.fml.common.eventhandler.Event;
+
+@RequiredArgsConstructor
+public class SettingsChangedEvent extends Event {
+    @Getter
+    private final SettingsRegistry settingsRegistry;
+
+    @Getter
+    private final SettingsRegistry.SettingKey<?> key;
+}