fix expandable header padding (#10927)

Author: a-hariti

src/components/expandable.tsx

@@ -36,6 +36,9 @@ const ExpandableWrapper = styled.div`
   border-left: 3px solid var(--accent-12);
   margin-bottom: 1rem;
   padding: 0.5rem 1rem;
+  h2 {
+    margin-top: 0;
+  }
 `;
 
 function slugify(str: string) {