improve SEO, add robots

src/app/layout.tsx

@@ -9,10 +9,9 @@ export const viewport: Viewport = {
 };
 
 export const metadata: Metadata = {
-  title:
-    "InvestingFIRE Calculator | Plan Your Financial Independence & Early Retirement",
+  title: "InvestingFIRE | Finance and Retirement Calculator",
   description:
-    "Achieve Financial Independence, Retire Early (FIRE) with the InvestingFIRE calculator. Get personalized projections and investing advice to plan your journey.",
+    "Achieve Financial Independence & Early Retirement! Plan your FIRE journey with the InvestingFIRE calculator and get personalized projections in buttersmooth graphs.",
 };
 
 const geist = Geist({

src/app/robots.ts

@@ -0,0 +1,11 @@
+import type { MetadataRoute } from "next";
+
+export default function robots(): MetadataRoute.Robots {
+  return {
+    rules: {
+      userAgent: "*",
+      allow: "/",
+    },
+    sitemap: "https://investingfire.com/sitemap.xml",
+  };
+}