Merge pull request gulpjs#532 from fritx/patch-1

Update CONTRIBUTING.md

Author: yocontra

CONTRIBUTING.md

@@ -7,8 +7,10 @@ Please contribute to this repository if any of the following is true:
 
 # How to contribute
 
-Prerequisites: familiarity with [GitHub PRs](https://help.github.com/articles/using-pull-requests) (pull requests) and issues.
-Knowledge of Markdown for editing `.md` documents
+Prerequisites:
+
+- familiarity with [GitHub PRs](https://help.github.com/articles/using-pull-requests) (pull requests) and issues
+- knowledge of Markdown for editing `.md` documents
 
 In particular, this community seeks the following types of contributions: