I have made an attempt to this, but far from complete.
I manually indexed the search engines of different websites in a common natural language interface:
When writing
"date parser MIT license stars > 1000"
It automatically suggests GitHub as a website that can support this query:
On mobile your site shows me that GitHub can support that query, but I’d like to be able to then tap on it and be taken to the GitHub search in question. At least on iOS with Safari, I could not find a way to be taken to the GitHub results by tapping on anything.
When the results appear, you have to press the small play button at the right side, then you will be navigated to GitHub to see the expected search results.
I tried it now on iOS with Safari. I tried "date parser mit license". It could be more intuitive though
https://quantleaf.com/?q=&t=query&run=false
You can see more examples on the website.