Merge pull request #8109 from cirosantilli/contributing-style-vs-min

State on CONTRIBUTING that people should fix line style of touched lines

CONTRIBUTING.md

@@ -101,7 +101,11 @@ For examples of feedback on merge requests please look at already [closed merge
 1. Contains functionality we think other users will benefit from too
 1. Doesn't add configuration options since they complicate future changes
 1. Changes after submitting the merge request should be in separate commits (no squashing). You will be asked to squash when the review is over, before merging.
-1. It conforms to the following style guides
+1. It conforms to the following style guides.
+    If your change touches a line that does not follow the style,
+    modify the entire line to follow it. This prevents linting tools from generating warnings.
+    Don't touch neighbouring lines. As an exception, automatic mass refactoring modifications
+    may leave style non-compliant.
 
 ## Style guides