make grouping clearer and update readme

src/app/components/Discord/DiscordButton.tsx

@@ -0,0 +1,14 @@
+import { Box, Button } from "@mui/material";
+export const DiscordButton = () => {
+  return (
+    <Box>
+      <Button
+        href="https://discord.gg/MDapvGyw"
+        target="_blank"
+        style={{ width: "100%" }}
+      >
+        Discord
+      </Button>
+    </Box>
+  );
+};