Fix footer link color - change from blue to light yellow for better contrast

[Copilot]

The footer links were using the default blue color (#428bca) which was hard to read against the black background, making them both difficult to read and visually unappealing.

Changes Made

Added CSS rules to site/css/custom.css to improve footer link visibility:

/* Footer link styling - light yellow for better contrast against black background */
footer a {
  color: #ffd700 !important;
}

footer a:hover {
  color: #ffed4a !important;
}

Visual Comparison

Before: Footer links were blue (#428bca) which was hard to read against black backgrounds
After: Footer links are now light yellow (#ffd700) with a lighter yellow hover state (#ffed4a)

Screenshots showing the improvement:

• Normal state: https://github.com/user-attachments/assets/189ef83f-1523-47ee-b982-653322cc5e69
• Hover state: https://github.com/user-attachments/assets/8a282f1c-0898-4bba-9047-882347392596

The change affects both the main page footer (in src/page-template.html) and blog post footers (in src/post-template.html), providing better contrast and readability while maintaining the site's aesthetic.

Fixes #33.

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.