style: adjust footer logo size and spacing

- Reduced logo dimensions from 20x20 to 15x15 pixels for better visual balance
- Updated height and width classes from h-20/w-20 to h-15/w-15 to match new design spec

src/components/Footer.tsx

@@ -8,7 +8,7 @@ export function Footer() {
         <div className="flex flex-col items-start justify-between gap-y-12 pt-16 pb-6 lg:flex-row lg:items-center lg:py-8">
           <div>
             <div className="flex items-center text-gray-900">
-              <img src="/src/images/logomark.svg" alt="Mycelium Logomark" className="h-20 w-20 flex-none" />
+              <img src="/src/images/logomark.svg" alt="Mycelium Logomark" className="h-15 w-15 flex-none" />
               <div className="ml-4">
                 <p className="text-base font-semibold">Project Mycelium</p>
                 <p className="mt-1 text-sm">Unleash the Power of Decentralization</p>