* Refactor: move has_long_markdown from view to helper, and change it from variable to method
* Fix: Article Posted Date and Author Card Posted Date do not match #8789
* Add test case for Article Posted Date and Author Card Posted Date do not match #8789
* Use our custom URL helper module instead of manually constructing URL
* Move long_markdown? from ArticlesHelper to ArticleDecorator
* Change method name from has_long_markdown? to long_markdown?
* Add test suites for long_markdown? method to ArticleDecorator spec
* Use << over +=
* Fix typo
* Remove unnecessary cache