x/pkgsite: search ranking ought to prioritize more recent major module versions

[cespare]

What is the URL of the page with the issue?

https://pkg.go.dev/search

What is your user agent?

N/A

Screenshot

For example, search for "xxhash":

https://pkg.go.dev/search?q=xxhash

What did you do?

Searched for "xxhash"

What did you expect to see?

The v2 module should be ranked above the old v1 module even if the v1 module has more importers or otherwise ranks higher according to the heuristics pkg.go.dev uses.

Even better, IMO, the v1 wouldn't even show up as a separate search result. The module would appear once and if you visit the page you would see the v2 by default with a way to browse the older module versions.

What did you see instead?

The v1 module appears as the first search result, encouraging new users to use an old version of my module rather than the new one.

[myitcv]

Related #36806 (comment)

[jba]

I'm uncomfortable showing v2 when v1 is more popular. Perhaps v2 is a misfire, and v1 is the better module (see New Coke).

I do think we should group all versions of a module together. Perhaps we can sort that subgroup by version, but mark the most popular in some way (or vice versa—sort by popularity and mark the latest—which I think I like better).