Fix README links
Fix README links

Fixed README links that had the full URL as text to bare URLs (GitHub
does linkify these), using the correct URL for the one where the link
text was correct but the href wasn't.

RayRutjes/frontend,circleci/frontend,prathamesh-sonpatki/frontend,RayRutjes/frontend,circleci/frontend,prathamesh-sonpatki/frontend,circleci/frontend