I have a little over 1000 stars (1044 at time of post) and have made $10 in Bitcoin (Which is worth less than $10 now). That being said, my project is extremely-side-projecty[1].
Others have discussed busies models, so it should be a simple calculation of how much you can charge for a model vs how much it will cost you to run your business and if you can live with the reminder after taxes etc... then I would say do it.
It looks like a very useful project that I will probably start using. Sadly, my usual workflow for gitignores is to grab one from a previous project of mine and adapt, or else Google a big project I know in the language I'm targeting, grab from there, and make a few adjustments. Your process looks much more efficient.
But how did you even make $10 in Bitcoins? I don't even see a donation link or address, much less a place to sign up for a paid plan.
I see a lot of potential, for example, you could expand a premium plan to include other project templates, like maybe travis.yaml, and the various .jshintrc and other ....rc's, perhaps). I'd pay $10/year for that, maybe more depending on how well it was done.
Or perhaps if it's just a side project you're not really interested in expanding.
Also, Bitcoin just realistically, Bitcoin isn't used by a lot of people, even in the developer community. It's great to include it as an add-on, but I'd think if you want to make money, you need to accept USD.
Others have discussed busies models, so it should be a simple calculation of how much you can charge for a model vs how much it will cost you to run your business and if you can live with the reminder after taxes etc... then I would say do it.
[1] - https://github.com/joeblau/gitignore.io