- topic : means help file location relative path (must not started with '/')
- file location : /helps/${topic}.${locale}.md
- The help(markdown) file is selected in response to the user's language information.
- help file finding order (ie. user language is 'ko-KR' and topic is 'about/things-factory' and fallback language is 'en')
- /helps/about/things-factory.ko-KR.md
- /helps/about/things-factory.ko.md
- /helps/about/things-factory.en.md
- /helps/about/things-factory.md