Added!
Note for future people interested, this is apparently not needed anymore, anyone can start a review on the FreeCAD pull requests. And your contributions will be there the same way, visible to all
About code style guides, no, we haven't anything really official, although many people have tried starting things like that... At the moment I'd say we look more to have things that are more or less well constructed and don't break anything. FreeCAD also being a very hybrid code with different languages and libraries makes it harder to get everyone to follow one determined code styling.