feat: add multiple UI components

This commit introduces a batch of UI components such as Accordion, Alert, Avatar, Badge, etc. Each component is provided with proper TypeScript type definitions. Reusable styling is catered for many of these using the `cn` utility for applying styles. Integration with `@radix-ui/react-*` libraries is also evident in some components for advanced and flexible functionality.

src/components/ui/skeleton.tsx

@@ -0,0 +1,15 @@
+import { cn } from "@/lib/utils"
+
+function Skeleton({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) {
+  return (
+    <div
+      className={cn("animate-pulse rounded-md bg-muted", className)}
+      {...props}
+    />
+  )
+}
+
+export { Skeleton }