Add CustomRecipe

Author: Kiber2009

src/main/java/io/github/kiber2009/plugin/contentapi/api/recipe/CustomRecipe.java

@@ -0,0 +1,11 @@
+package io.github.kiber2009.plugin.contentapi.api.recipe;
+
+import org.bukkit.inventory.ItemStack;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
+
+public interface CustomRecipe {
+    @NonNull ItemStack getResult();
+
+    boolean match(final @Nullable ItemStack @NonNull [] matrix);
+}