Copy static files over to the output directory.

src/command/build/runner.rs

@@ -25,6 +25,7 @@ pub(crate) async fn build_site(args: BuildArgs) -> Result<(), CustomError> {
     renderer.render_blog_posts(&config).await?;
     renderer.render_blog_stream(&config).await?;
     renderer.render_stylesheets().await?;
+    renderer.copy_static_files(&config).await?;
 
     Ok(())
 }