Implement Config-Driven Bento Grid for Quick Links

This PR refactors the bento grid on the Quick Links page (/bento) to be fully configuration-driven using Jekyll's data files. Now all bento grid cards are managed through a single YAML configuration file, making the grid more maintainable and easier to update.

Changes

• Created a new data-driven approach for the bento grid using _data/bento_grid.yml
• Refactored the bento.html template to render cards from the configuration
• Added support for different card sizes through configuration (large, tall, wide)
• Applied BEM naming conventions consistently throughout the codebase

How to use

To add or modify bento cards:

1. Edit the _data/bento_grid.yml file
2. Each card is defined as a YAML object with properties like title, description, icon, etc.
3. Cards appear in the same order as defined in the YAML file

Example card configuration:

- title: "HydPy Hack 2025"
  url: "/hydpyhack-2025.html"
  icon: "fas fa-calendar-alt"
  background: "bg-primary"
  text_color: "text-white"
  description: "Join us for the biggest Python hackathon in Hyderabad"
  button_text: "Learn More"
  button_class: "btn-light btn-lg"
  external: false
  size: "large"  # Optional: large, tall, wide