docs: adding autoprefixer config story to list

Close #6188

Author: markgoho

docs/documentation/stories.md

@@ -23,4 +23,5 @@
  - [Internationalization (i18n)](stories/internationalization)
  - [Serve from Disk](stories/disk-serve)
  - [Code Coverage](stories/code-coverage)
- - [Application Environments](stories/application-environments)
+ - [Application Environments](stories/application-environments)
+ - [Autoprefixer Configuration](stories/autoprefixer)