Rails integration link is offline!

[Rynaro]

The Ruby on Rails integration documentation website url is offline. The url now redirects to an webpage showing that "URL is now available to purchase".
I think, its a good idea removing this topic from README

[dbox]

Hi @Rynaro. Thanks for the lookout. Want to make a PR for this?

[Rynaro]

The pull request is here. 😃
I've removed the Rails link, and adjusted the link of CDN too.

[dbox]

Whoot! thnx.