Number of exhibitions per page

Summary: Add an option to select the number of exhibitions per page

Description: Implement a feature allowing users to select the number of exhibitions displayed per page on the screen.

Expected outcome:

• A fully functional feature enabling users to specify the number of exhibitions per page.
• Updated UI reflecting the selected number of exhibitions.

Acceptance Criteria:

• Users can choose the number of exhibitions (e.g., 12, 24, 36, 48).
• The layout adjusts dynamically based on the selection.
• Works across all supported browsers and screen sizes.