Design the new download page
_Originally created by @sajolida on [#14627 (Redmine)](https://public-redmine-archive.tails.boum.org/code/issues/14627)_
1\. Design new wireframes
2\. Test the wireframes on paper
3\. Write the resulting HTML code
Let’s say that this tickets covers everything needed to have a download
page that works with the new extension and has enough CSS to be usable.
The integration with the other pages and the replacement of DAVE will
happen on tails/tails#14630.
The polishing of the CSS will happen on tails/tails#14921.
Feature Branch: master
Parent Task: tails/tails#12328
### Related issues
- **Blocks** tails/tails#14628
- **Blocks** tails/tails#14629
issue