Newcomers_Guide.rst: Fix broken link
Newcomers_Guide.rst: Fix broken link

"Fixes a previously broken link to an updated one."

Fixes https://github.com/coala/documentation/issues/128

coala/documentation,AnishHota/documentation,coala/documentation,kshitijkg01/documentation,Kevchen/documentation,Akki356/documentation,Warewolf96/documentation,tamj0rd2/documentation,lusy/coala-documentation,virresh/documentation,cristinabuciu/documentation,abhishekbundela/documentation,coala/documentation,Asnelchristian/documentation,rhemon/documentation