Adding color to blocquote links in documentation

Fixes #6377

We still want the inside of the blockquote to be fully colored with only one color... except for links that hev to be a bit different to spot them out.

You can see an example here:
https://docs.docker.com/userguide/usingdocker/
In the first note of the page, you can't notice the link until you have your mouse hovering it.