x/website: dl page is not designed for large numbers of files

[heschi]

go.dev/dl is already pretty crowded. #53862 means that each go1.21 release will have maybe 20 more files. I think we should do something to mitigate that. It could be as simple as adding a zippy around the secondary ports section, but there's a lot of room for further improvement.

Marking as a release blocker; it's not so critical but it'd be nice to get done before the final release.

cc @golang/release

[gopherbot]

Change https://go.dev/cl/486555 mentions this issue: _content: add toggle to display other ports on download page