Add PRD for EnergieProfis

Add Product Requirements Document for the EnergieProfis platform, outlining product overview, core features, technical architecture, design system, routing, admin panel requirements, authentication, monetization, SEO, development phases, success metrics, risk assessment, and future roadmap.

src/pages/Index.tsx

@@ -1,12 +1,19 @@
-// Update this page (the content is just a fallback if you fail to update the page)
+import Header from "@/components/Header";
+import HeroSection from "@/components/HeroSection";
+import EnergyTypesSection from "@/components/EnergyTypesSection";
+import WhyChooseUsSection from "@/components/WhyChooseUsSection";
+import Footer from "@/components/Footer";
 
 const Index = () => {
   return (
-    <div className="min-h-screen flex items-center justify-center bg-background">
-      <div className="text-center">
-        <h1 className="text-4xl font-bold mb-4">Welcome to Your Blank App</h1>
-        <p className="text-xl text-muted-foreground">Start building your amazing project here!</p>
-      </div>
+    <div className="min-h-screen">
+      <Header />
+      <main>
+        <HeroSection />
+        <EnergyTypesSection />
+        <WhyChooseUsSection />
+      </main>
+      <Footer />
     </div>
   );
 };