Fix checkstyle issues

src/main/java/io/netty/buffer/api/pool/PoolChunk.java

@@ -168,7 +168,8 @@ final class PoolChunk implements PoolChunkMetric {
     PoolChunk prev;
     PoolChunk next;
 
-    PoolChunk(PoolArena arena, Buffer base, Object memory, int pageSize, int pageShifts, int chunkSize, int maxPageIdx) {
+    PoolChunk(PoolArena arena, Buffer base, Object memory, int pageSize, int pageShifts, int chunkSize,
+              int maxPageIdx) {
         this.arena = arena;
         this.base = base;
         this.memory = memory;

src/main/java/io/netty/buffer/api/pool/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2021 The Netty Project
+ *
+ * The Netty Project licenses this file to you 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:
+ *
+ *   https://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.
+ */
+/**
+ * A pooling {@link io.netty.buffer.api.BufferAllocator} implementation based on jemalloc.
+ */
+package io.netty.buffer.api.pool;