Addition to readme

[M1sterPl0w]

Hi,

First of all, thanks for creating this wonderful piece of software.
I am fairly new to React and I was trying to get your example working with the following steps:

• npm install react-d3-graph
• add Graph tag and call backs into a component.

After this I did get several error message that it was missing d3-drag, etc etc.
After a while I thought maybe I should install d3 (npm install d3), this action did the trick. Maybe you could add this to the readme? So it is more noob friendly?

Kind regards,

Jeroen

[danielcaldas]

Hi there @M1sterPl0w! Thanks a lot for the input, that's right you need to install d3 and react yourself as they are peer-dependencies. This might not be very clear, I will update the README.md with this information.

[danielcaldas]

Closing, README.md updated with #191