refactor: adjust small styling

Author: kiaking

src/client/theme-default/styles/components/vp-doc.css

@@ -29,7 +29,7 @@
 }
 
 .vp-doc h3 {
-  margin: 48px 0 0;
+  margin: 32px 0 0;
   letter-spacing: -0.01em;
   line-height: 28px;
   font-size: 20px;