add app readme

lots of styling improvements
fix dark/bright mode

app/src/components/Panel.tsx

@@ -0,0 +1,15 @@
+import { FC, ReactNode } from "react";
+
+const Panel: FC<{ title: string; children: ReactNode }> = ({
+  title,
+  children,
+}) => {
+  return (
+    <div>
+      <h3>{title}</h3>
+      <div>{children}</div>
+    </div>
+  );
+};
+
+export default Panel;