Call me OCD, but I'm going to break this down.

* You're adding another second-person pronoun in this version, which seems a little overboard to me. I like reading web pages about things, not always ones that address me very aggressively. I think this could be OK in this context.
* The adverbial prepositional phrase starting with "with" applies to the verb "grow", making this look like you already *have* more contributors and you want the project to grow. I would change it to "to have", or rethink the sentence altogether.

My suggestion: "How can I bring more contributors to my project?"

The first-person is less aggressive but just as engaging; the active "bring" verb will resonate with what people want for their projects, and the preposition "to" is more active too.