create courses page

[ihor-bobyr]

create https://programming.org.ua/en/courses https://github.com/shpp/programming.org.ua/tree/master/src/pages/courses-page

• [x] reuse https://github.com/ihor-bobyr/programming.org.ua/issues/18
• [x] try to reuse component for faq question from https://github.com/ihor-bobyr/programming.org.ua/issues/1 manifesto section (reuse styles and javascript logic, template will be separate)
• [x] implement education for teens section
• [x] details section should be opened by default *but should be closable