Pulling all pending Bukkit-JavaDoc changes

A special thanks goes to @aerouk for almost all of the changes found here.

By: Wesley Wolfe <weswolf@aol.com>

paper-api/src/main/java/org/bukkit/block/DoubleChest.java

@@ -6,6 +6,9 @@ import org.bukkit.inventory.DoubleChestInventory;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryHolder;
 
+/**
+ * Represents a double chest.
+ */
 public class DoubleChest implements InventoryHolder {
     private DoubleChestInventory inventory;