✨(demo) add app demo

This demo is useful to test in the real usage of the design system as a real
user that will generate its own customized design tokens, implements the design
system's components, etc ...

apps/demo/src/cunningham-tokens.css

@@ -0,0 +1,6 @@
+:root {
+	--c--colors--primary: purple;
+	--c--colors--secondary: #DA0000;
+	--c--text--primary: purple;
+	--c--text--secondary: #DA0000;
+}