Merge branch 'mk/author-preparation-docs' into 'master'

Encourage MR author preparation in Code Review Guidelines documentation

See merge request gitlab-org/gitlab-ce!23360

doc/development/code_review.md

@@ -85,6 +85,23 @@ If an author is unsure if a merge request needs a domain expert's opinion, that'
 usually a pretty good sign that it does, since without it the required level of
 confidence in their solution will not have been reached.
 
+Before the review, the author is requested to submit comments on the merge
+request diff alerting the reviewer to anything important as well as for anything
+that demands further explanation or attention.  Examples of content that may
+warrant a comment could be:
+
+- The addition of a linting rule (Rubocop, JS etc)
+- The addition of a library (Ruby gem, JS lib etc)
+- Where not obvious, a link to the parent class or method
+- Any benchmarking performed to complement the change
+- Potentially insecure code
+
+Do not add these comments directly to the source code, unless the
+reviewer requires you to do so.
+
+This
+[saves reviewers time and helps authors catch mistakes earlier](https://www.ibm.com/developerworks/rational/library/11-proven-practices-for-peer-review/index.html#__RefHeading__97_174136755).
+
 ### The responsibility of the maintainer
 
 Maintainers are responsible for the overall health, quality, and consistency of