feat: add plain-language description under CommitPulse heading (JhaSourav07#1348)

## Description
Closes JhaSourav07#1178

Added a short plain-language description under the CommitPulse heading
so first-time visitors immediately understand what the product does.

## Pillar
- [ ] Other (Bug fix, refactoring, docs)

## Checklist before requesting a review:
- [x] I have read the `CONTRIBUTING.md` file.
- [x] I have tested these changes locally (`localhost:3000`).
- [x] My commits follow the Conventional Commits format.
- [x] I have made sure that i have only one commit to merge in this PR.

Author: shaarvitripathi2-dotcom

app/page.test.tsx

@@ -164,9 +164,9 @@ describe('LandingPage', () => {
 
   it('renders the main heading', () => {
     render(<LandingPage />);
-    expect(screen.getByText(/Elevate Your/i)).toBeDefined();
-    expect(screen.getByText('Contribution')).toBeDefined();
-    expect(screen.getByText(/Story/i)).toBeDefined();
+    const heading = screen.getByRole('heading', { level: 1 });
+    expect(heading.textContent).toMatch(/Elevate Your/i);
+    expect(heading.textContent).toMatch(/Contribution Story/i);
   });
 
   it('renders the input field empty by default', () => {

app/page.tsx

@@ -204,8 +204,8 @@ export default function LandingPage() {
             transition={{ delay: 0.3 }}
             className="mx-auto max-w-2xl text-sm sm:text-lg leading-relaxed text-gray-600 dark:text-white/65 md:text-xl "
           >
-            Stop settling for flat grids. Generate high-fidelity, 3D isometric monoliths that
-            visualize your coding rhythm with professional precision.
+            CommitPulse converts your GitHub commit history into a live, 3D animated badge. The more
+            you commit, the taller your city grows! Embed it in your profile README with one line.
           </motion.p>
         </div>