Collapsible Menu
How it works:
1. HTML Structure: Each collapsible menu item has a header (menu-header) and a content section (menu-content).
2. CSS Styling: The menu-content is initially hidden by setting max-height to 0 and using overflow: hidden.
3. JavaScript: On clicking a menu-header, the script toggles the max-height of the associated menu-content.
This code ensures a smooth expand/collapse animation and closes other menus when one is opened.
