message: feat(webpack): implement preview
diff: @@ -34,7 +34,10 @@ pub fn preview(
  .post(create_address)
  .body(publish::build_js_script()?)
  .send(),
  - ProjectType::Webpack => panic!("unimplemented"),
  + ProjectType::Webpack => client
  + .post(create_address)
  + .multipart(publish::build_webpack_form()?)
  + .send(),
  };
  let p: Preview = serde_json::from_str(&res?.text()?)?;
  