I hate to ask this, but how is this fundamentally different from: https://www.npmjs.com/search?
Also, you can "filter out" some results which is something you can't do (yet) with npmjs.com - I search a lot this way (try something first then filter out what I dont care, etc.)
Also, there is more info (stars, activity, latest release, ...) npm gives shows only name, description and current version number which was not enough for me
Plain github search usually worked better, but even there I've usually had to open first two pages of projects just to see which ones are dead.
So the idea is that this works for me and just maybe it could work for you too :)