Add PlayerRecipeDiscoverEvent and methods to (un/)discover recipes

By: Parker Hawke <hawkeboyz2@hotmail.com>

paper-api/src/main/java/org/bukkit/event/player/PlayerRecipeDiscoverEvent.java

@@ -0,0 +1,50 @@
+package org.bukkit.event.player;
+
+import org.bukkit.NamespacedKey;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+
+/**
+ * Called when a player discovers a new recipe in the recipe book.
+ */
+public class PlayerRecipeDiscoverEvent extends PlayerEvent implements Cancellable {
+
+    private static final HandlerList handlers = new HandlerList();
+
+    private boolean cancel = false;
+    private final NamespacedKey recipe;
+
+    public PlayerRecipeDiscoverEvent(Player who, NamespacedKey recipe) {
+        super(who);
+        this.recipe = recipe;
+    }
+
+    /**
+     * Get the namespaced key of the discovered recipe.
+     *
+     * @return the discovered recipe
+     */
+    public NamespacedKey getRecipe() {
+        return recipe;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancel;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancel = cancel;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}