text: Title: Mark private modules and functions as private
  Body: ## Problem
  
  <!-- A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] -->
  
  Currently we do not have a strict public API contract i.e. the public modules, classes and functions we provide are not treated any differently than the private ones. We should easily and correctly indicate to users which parts of our API are public not.
  
  ## Suggested solution
  
  <!-- A clear and concise description of what you want to happen. -->
  
  We should rename all modules and functions to indicate that they are private (e.g. `prisma.binaries` -> `prisma._binaries`) and then export all public modules, classes and functions in the base package.
  
  ## Additional context
  
  <!-- Add any other context or screenshots about the feature request here. -->
  
  This is what Encode do with https://github.com/encode/httpx