Add font faces to design system

[dcrjodle]

Export these as:
/* Fonts */
--font-sans: 'Geist';
--font-serif: 'Geist';
--font-mono: 'Geist Mono';

/* Geist Sans Font Family */
@font-face {
font-family: 'Geist';
src: url('/fonts/Geist/webfonts/Geist-Regular.woff2') format('woff2');
font-weight: 400;
font-style: normal;
font-display: swap;
}

@font-face {
font-family: 'Geist';
src: url('/fonts/Geist/webfonts/Geist-Medium.woff2') format('woff2');
font-weight: 500;
font-style: normal;
font-display: swap;
}

@font-face {
font-family: 'Geist';
src: url('/fonts/Geist/webfonts/Geist-SemiBold.woff2') format('woff2');
font-weight: 600;
font-style: normal;
font-display: swap;
}

@font-face {
font-family: 'Geist';
src: url('/fonts/Geist/webfonts/Geist-Bold.woff2') format('woff2');
font-weight: 700;
font-style: normal;
font-display: swap;
}

/* Geist Mono Font Family */
@font-face {
font-family: 'Geist Mono';
src: url('/fonts/GeistMono/webfonts/GeistMono-Regular.woff2') format('woff2');
font-weight: 400;
font-style: normal;
font-display: swap;
}

@font-face {
font-family: 'Geist Mono';
src: url('/fonts/GeistMono/webfonts/GeistMono-Medium.woff2') format('woff2');
font-weight: 500;
font-style: normal;
font-display: swap;
}

@font-face {
font-family: 'Geist Mono';
src: url('/fonts/GeistMono/webfonts/GeistMono-SemiBold.woff2') format('woff2');
font-weight: 600;
font-style: normal;
font-display: swap;
}

@font-face {
font-family: 'Geist Mono';
src: url('/fonts/GeistMono/webfonts/GeistMono-Bold.woff2') format('woff2');
font-weight: 700;
font-style: normal;
font-display: swap;
}