message: fix(techdocs-404): throw error
diff: @@ -34,7 +34,9 @@ import { TechDocsPageWrapper } from './TechDocsPageWrapper';
  const useFetch = (url: string) => {
  const state = useAsync(async () => {
  const response = await fetch(url);
  - if (response.status === 404) return '404';
  + if (response.status === 404) {
  + return new Error('Page not found');
  + }
  const raw = await response.text();
  return raw;
  }, [url]);
  @@ -116,7 +118,7 @@ export const Reader = () => {
  }
  }, [shadowDomRef, state, componentId, path, navigate]);
  - if (state.value === '404') return <TechDocsNotFound />;
  + if (state.value instanceof Error) return <TechDocsNotFound />;
  return (
  <>
  