add some Generator generics for PHPStan

src/pocketmine/inventory/CraftingManager.php

@@ -254,6 +254,7 @@ class CraftingManager{
 	 * @param Item[] $outputs
 	 *
 	 * @return CraftingRecipe[]|\Generator
+	 * @phpstan-return \Generator<int, CraftingRecipe, void, void>
 	 */
 	public function matchRecipeByOutputs(array $outputs) : \Generator{
 		//TODO: try to match special recipes before anything else (first they need to be implemented!)

src/pocketmine/network/mcpe/protocol/BatchPacket.php

@@ -91,6 +91,7 @@ class BatchPacket extends DataPacket{
 
 	/**
 	 * @return \Generator
+	 * @phpstan-return \Generator<int, string, void, void>
 	 */
 	public function getPackets(){
 		$stream = new NetworkBinaryStream($this->payload);