feat: add ModLoaded callback event on Fabric (#346)

Co-authored-by: William <will27528@gmail.com>

fabric/src/main/java/net/william278/husksync/FabricHuskSync.java

@@ -49,6 +49,7 @@ import net.william278.husksync.database.MongoDbDatabase;
 import net.william278.husksync.database.MySqlDatabase;
 import net.william278.husksync.database.PostgresDatabase;
 import net.william278.husksync.event.FabricEventDispatcher;
+import net.william278.husksync.event.ModLoadedCallback;
 import net.william278.husksync.hook.PlanHook;
 import net.william278.husksync.listener.EventListener;
 import net.william278.husksync.listener.FabricEventListener;
@@ -206,6 +207,8 @@ public class FabricHuskSync implements DedicatedServerModInitializer, HuskSync,
 
         // Check for updates
         this.checkForUpdates();
+
+        ModLoadedCallback.EVENT.invoker().post(FabricHuskSyncAPI.getInstance());
     }
 
     private void onDisable() {

fabric/src/main/java/net/william278/husksync/event/ModLoadedCallback.java

@@ -0,0 +1,39 @@
+/*
+ * This file is part of HuskSync, licensed under the Apache License 2.0.
+ *
+ *  Copyright (c) William278 <will27528@gmail.com>
+ *  Copyright (c) contributors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.william278.husksync.event;
+
+import net.fabricmc.fabric.api.event.Event;
+import net.fabricmc.fabric.api.event.EventFactory;
+import net.william278.husksync.api.HuskSyncAPI;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+
+public interface ModLoadedCallback {
+
+    @NotNull
+    Event<ModLoadedCallback> EVENT = EventFactory.createArrayBacked(
+            ModLoadedCallback.class,
+            (listeners) -> (api) -> Arrays.stream(listeners).forEach(listener -> listener.post(api))
+    );
+
+    void post(@NotNull HuskSyncAPI api);
+
+}