fix: update telemetry source to 'template-builder-demo'

Author: andrii-harbour

packages/template-builder/demo/src/App.tsx

@@ -251,7 +251,7 @@ export function App() {
           telemetry={{
             enabled: true,
             metadata: {
-              source: 'template-builder',
+              source: 'template-builder-demo',
             },
           }}
           onReady={handleReady}