If I see more than one language in a repo or the developers' names sound foreign to me, I'm more likely to check out their profile.
I always love to find out more about (development) culture in other parts of the world. Can you elaborate a bit on how it's 'bold' to use your own language in a README or docs? Do you find it annoying?
I mean, I’m a Japanese but how I notice a developer is a good fellow countrymen is usually through noticing telltale signs and chasing them down, not because there’s a filename in the language I speak at the root of a repository.