Please review and translate: new download landing page

Hello all

Thanks Jesse Rhodes [1], we have a new landing page where people are redirected when clicking the Download button on the homepage, explaining the basics about the downloaded images and links to more info or other downloads.

[1] see https://salsa.debian.org/webmaster-team/webwml/-/merge_requests/699 for details about the proposal

We have a project of reorganising all the CD/distrib section and produce a new "download section" (see bug #819664 Re-organise the CD / download pages to make them more useful), this maybe is not capable to close that bug, but I think it is a good proposal for now that can help with some other bugs (#720989 unexperienced users fail to download installation media especially for usb drives, #640054 Download pages should have prominent links to image verification instructions, #797342 simple and easy to use download page, maybe others).

We appreciate proofreads and translations.

I'll update link of the download button in homepage (/index.wml) for the different languages later today, if nobody beats me to it.

Kind regards,