wildcard all the other variants

src/main.rs

@@ -53,16 +53,12 @@ fn visit_ast<'a, W: Write>(opt: &Opt, out: &mut W, node: &'a AstNode<'a>) -> Res
                 out.write(&code_block.literal)?;
             }
         }
-        NodeValue::List(_) | NodeValue::Item(_) | NodeValue::Document => {
+        _ => {
             // recurse
             for child in node.children() {
                 visit_ast(opt, out, child)?;
             }
         }
-        NodeValue::Heading(_) | NodeValue::BlockQuote | NodeValue::Paragraph => {
-            // don't do anything
-        }
-        _ => todo!("unsupported type {:?}", ast.value),
     }
 
     Ok(())