To improve the plugin overall

1. Customizable GUI. Allow configuration with the plugin GUI for server owners to decide

• the type of block we want to display
• personalize GUI item titles and lores.
• personalize GUI menu title per chest and main menu..

2. Useful placeholders such as how many items are in the chest (which already exist by default)

• to show the type of items in the chest, say, Diamond Sword 1x, Gold_Ingot 256x for exmaple.