Center PDF title and improve code/list formatting

- Centered note title in PDF exports for better visual balance
- Increased inline code font size from 0.9em to 1.1em for better readability
- Removed paragraph margins inside list items to fix spacing issues

src/components/NoteEditor.tsx

@@ -167,6 +167,7 @@ export function NoteEditor({ note, onUpdateNote, fontSize, onUnsavedChanges }: N
       titleElement.style.fontSize = '24px';
       titleElement.style.fontWeight = 'bold';
       titleElement.style.color = '#000000';
+      titleElement.style.textAlign = 'center';
       container.appendChild(titleElement);
       
       // Clone and add content