improve docs

Author: thejackshelton

apps/website/src/routes/docs/headless/carousel/index.mdx

@@ -184,7 +184,7 @@ Both SSR and CSR are supported. In this example, we conditionally render the car
 
 <Showcase name="csr" />
 
-## Mousewheel
+### Mousewheel
 
 The carousel component also supports mousewheel navigation in the case of vertical carousels.