Codestyle.rst: Add line continuation policy
Codestyle.rst: Add line continuation policy

We are already enfocing it, but it's not covered by PEP8

Closes https://github.com/coala-analyzer/documentation/issues/27

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