Add a "trending" search option & section on the front page

### Description

Could we add a `trending` search option & front-page section, highlighting packages that are gaining popularity (i.e. have a quickly increasing downloads number in time period T (e.g. "Last 30 days")?

The constructs.dev discovery experience currently prioritizes (via the search sorting options and "featured" section on the front page) constructs that are:
* All-time popular
* Recently published
* Have names that come early in the alphabet (A-Z sorting)
* Hand-picked featured entries (requires maintenance)

Other than the first option (which contains packages most users already know about, e.g. "AWS CDK" and "Constructs"), there is no good way to quickly see what packages many people find useful, especially recent ones. Because of this, I don't find the constructs.dev website useful, because visiting it more frequently doesn't let me know about cool new things, that are getting traction.

### Use Case

Highlight new constructs many users find useful (other than ones everybody knows about already, e.g. official AWS packages), which could promote users to create more & better packages and promote them on other platforms.

### Other information

_No response_

The issue points to the discovery experience, search sorting options, and the front-page featured section; start by tracing those existing entry points. Clarify the downloads-growth metric and time window before implementation, then verify that a trending search option and front-page section surface packages gaining popularity.

Written by the indexing model from the issue text.