Whitelist srcset for responsive images

[franciscop]

I am creating a repository where different sized images would be really nice for mobile version. Short story long, I've seen there's some html allowed including <img> and the attribute src, so I propose also allowing srcset for responsive images like this:

:attributes => {
  'a'          => ['href'],
  'img'        => ['src', 'srcset', 'longdesc'],
  'div'        => ['itemscope', 'itemtype'],
  ...

[franciscop]

Although looking more into it, srcset is dependent on the resolution and not on the device width. I'd normally use media queries, but that's a lot of css that is probably not allowed in github. Can anyone think of another solution to allow for different images in different device sizes?

Maybe a couple of attributes called data-desktop and data-mobile or others could work, but that'd require some css in your part and it's highly opinionated