Remove "getting started" from articles index page

[Dumindaaa]

Since a link to 'getting started' article is contained within the 'onboarding' section of the articles list page, and also, since the button on the articles category page also takes the user to the article itself, it doesn't need its own section on the articles list page

[kelshmo]

• [x] remove get-started category from article
• [x] remove getting started section from index page using logic

[kelshmo]

Will also impact #704.