docs: update CONTRIBUTING.md

Co-Authored-By: June Blender <[email protected]>

Author: mattsb42-aws

CONTRIBUTING.md

@@ -8,7 +8,7 @@ information to effectively respond to your bug report or contribution.
 
 
 ## Security issue notifications
-If you discover a potential security issue in this project we ask that you notify AWS/Amazon Security via our [vulnerability reporting page](http://aws.amazon.com/security/vulnerability-reporting/). Please do **not** create a public github issue.
+If you discover a potential security issue in this project, notify AWS/Amazon Security by using our [vulnerability reporting page](http://aws.amazon.com/security/vulnerability-reporting/). Please do **not** create a public GitHub issue.
 
 
 ## Reporting Bugs/Feature Requests