Add support for babel-plugin-flow-react-proptypes

[FezVrasta]

The problem

react-docgen isn't very reliable, and doesn't work at all with styled components.

Proposed solution

Allow to generate the documentation from React PropTypes autogenerated with babel-plugin-flow-react-proptypes starting from the Flow types.

Alternative solutions

Fix react-docgen, but it's not trivial.

Additional context

I think it's a low hanging fruit that will improve the quality of the generated documentation for Flow users. It may even be used as a fallback solution if react-docgen fails.

[sapegin]

Feel free to send a pull request for that!

[FezVrasta]

@sapegin may you point me to the right direction? What are the functions I will most likely need to change?

[sapegin]

Unfortunately I have no idea how to approach this ;-£ I'd look into react-docgen 4.0.0 because they've added some support for user's Babel config files. It could be useful here.