added shell check method

src/xyz/soper/arty/item/Shell.java

@@ -1,5 +1,7 @@
 package xyz.soper.arty.item;
 
+import org.bukkit.ChatColor;
+import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
 
 import java.util.List;
@@ -33,4 +35,17 @@ public class Shell {
         this.failChance = failChance;
     }
 
+    /**
+     * Checks if the item stack is a shell
+     * @param item ItemStack to check against
+     * @return True if item is an arrow with a gray name "Shell"
+     */
+    public static boolean isShell(ItemStack item){
+        if(item.getType() == Material.ARROW
+                && item.hasItemMeta()
+                && item.getItemMeta().hasDisplayName()
+                && item.getItemMeta().getDisplayName().equals(ChatColor.GRAY + "Shell")) return true;
+        return false;
+    }
+
 }