SPIGOT-4911: Cannot add firework rocket as charged projectile in crossbow

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/inventory/meta/CrossbowMeta.java

@@ -37,7 +37,8 @@ public interface CrossbowMeta extends ItemMeta {
      * Adds a charged projectile to this item.
      *
      * @param item projectile
-     * @throws IllegalArgumentException if the projectile is not an arrow
+     * @throws IllegalArgumentException if the projectile is not an arrow or
+     * firework rocket
      */
     void addChargedProjectile(@NotNull ItemStack item);
 }