Add option to sort contributors alphabetically by name

[Manu77211]

The contributors list is currently displayed in ID order. Adding a sort button (e.g., "Sort A-Z") would help users find contributors quickly in the large list.

Proposed changes:

• Add a "Sort A-Z" / "Sort Z-A" button near the search box in index.html.
• Modify render or add a new function in main.js to sort the array by fullname.
• Preserve pagination and search functionality.

This makes navigation easier for users browsing the list.

Assign this issue to me so I can work on it.

[Manu77211]

i have made changes ,review my pull request