Add k6 studio docs initial content

[heitortsergent]

Adds the initial content for the k6 Studio docs.

• [x] Remove Tutorials section
• [x] Add Set up folder
  • [x] Add Installation page
  • [x] Add Settings page
  • [x] Add Usage report page (link to k6 OSS Usage report page)
• [x] Fill out the Troubleshooting page
• [x] Get started guide
  • [x] Finish the Get started guide instructions (@Llandy3d)
  • [x] Add screenshots to Get started guide (@heitortsergent)
• [x] Add screenshots for components
• [x] Add Parameterization rule description
• [x] Update screenshots with "Public preview" header (I updated the screenshots with the latest version, and removed the top header in case we want to use screenshots from Windows or macOS)