Add reusable component for statistic card

Author: NorbertLoh

frontend/peerprep/app/components/statscard.tsx

@@ -0,0 +1,18 @@
+import { Card, Text } from "@mantine/core";
+
+export default function StatsCard({
+  title,
+  stat,
+  color,
+}: {
+  title: string;
+  stat: string;
+  color: string;
+}) {
+  return (
+    <Card shadow="sm" padding="lg">
+      <Text fw={700} ta="center" c="white">{stat}</Text>
+      <Text c={color} ta="center">{title}</Text>
+    </Card>
+  );
+}