Responsive Navbar with Hamburger Menu

On smaller devices, hide the home and about links in the navbar and place them inside a hamburger menu. This will make the navbar more compact and easier to use on mobile devices.

No file or test is named; first locate the existing navbar entry point and inspect how the home and about links are rendered at mobile widths. Done means those links are hidden from the compact navbar, available through a hamburger menu, and usable on smaller devices.

Written by the indexing model from the issue text.