Suggestion: Add Rekit Link

[andrew-h-lee]

On the README.md Alternatives Headline, is there any consideration to add the Rekit Toolkit just to inform Users of different approaches?

[gaearon]

We don’t intend to link to tools that ask users to maintain their own Webpack configurations.

We think this has caused a lot of issues associated with React community, and so we will promote approaches that abstract over the underlying configuration (even if they let you customize it, like nwb does).

Please see #580 for more discussion about this.