acecode

1. add another transparent background image because `background: url(...)` is _not working_ idea from [jakearchibald(At)chromium.org](https://bugs.chromium.org/p/chromium/issues/detail?id=495643#c8) 2. add no-repeat

if the placeholder is `used` at a `path`, the real middleware(s) will be `used` at the same `path` ``` app.use('/static', function staticPlaceholder(req, res, next ){ next() }); ```