Change size of preview images and add hash generator to name

[lucasvazq]

A tener en cuenta:

Images must be less than 5MB in size. https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/markup

Min image size: 600, Max image size: 1080 https://developers.facebook.com/docs/sharing/best-practices#images Tags to review og:image:secure_url og:image:url og:image

yandex has limit in the image size too

The hash in the name is to generate an appropriated cache preview-600x600-1231234

Add integrity

https://es.stackoverflow.com/questions/217769/qu%C3%A9-significa-integrity-en-la-inclusi%C3%B3n-de-esta-librer%C3%ADa-qu%C3%A9-pasa-si-la-omito

and crossorigin https://stackoverflow.com/a/41794176/10712525 https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity

[subzero-taringuero[bot]]

Thanks for opening this issue!