CTRT cleanup of artifacts page

What does this MR do?

This is a CTRT cleanup of the job artifacts page: https://docs.gitlab.com/ee/ci/pipelines/job_artifacts.html

While there is a lot of tweaking in this page, it's actually not that bad. It was cleaned up about 2 years ago and it has just "drifted" in the many edits since then. We've also got better CTRT standards that we can follow now, further improving the page.

Key changes

• Create job artifacts: Had multiple examples in one section. These are now separated into individual "with" tasks.
• Renamed to easier to parse "With/Without" subsections:
  • Use CI/CD variable...
  • Exclude files...
  • Add untracked files...
• Downloading artifacts details grouped together under Download job artifacts
  • Browse job artifacts: Combined into the Download job artifacts for now.
  • How search for job artifacts works: Details about downloaded artifacts, incorporated into Download job artifacts section.
• Retrieve job artifacts for other projects: Deleted, was purely about API, repeating details already explained in API docs.
• When job artifacts are deleted: Deleted, was repeating a crosslink already shared in other (more relevant) places in this doc.
• Keep artifacts from the most recent successful jobs: Was nested wrong, moved back H2.
• Troubleshooting: Copy edits.

Before & After

Readability: Before 8.03 - / After - 7.99

Before	After

Related issues

Related to #391443 (closed)

Author's checklist

• Optional. Consider taking the GitLab Technical Writing Fundamentals course.
• Follow the:
  • Documentation process.
  • Documentation guidelines.
  • Style Guide.
• If you're adding or changing the main heading of the page (H1), ensure that the product tier badge is added.
• If you are a GitLab team member, request a review based on:
  • The documentation page's metadata.
  • The associated Technical Writer.

If you are a GitLab team member and only adding documentation, do not add any of the following labels:

• ~"frontend"
• ~"backend"
• ~"type::bug"
• ~"database"

These labels cause the MR to be added to code verification QA issues.

Reviewer's checklist

Documentation-related MRs should be reviewed by a Technical Writer for a non-blocking review, based on Documentation Guidelines and the Style Guide.

If you aren't sure which tech writer to ask, use roulette or ask in the #docs Slack channel.

• If the content requires it, ensure the information is reviewed by a subject matter expert.
• Technical writer review items:
  • Ensure docs metadata is present and up-to-date.
  • Ensure the appropriate labels are added to this MR.
  • Ensure a release milestone is set.
  • If relevant to this MR, ensure content topic type principles are in use, including:
    • The headings should be something you'd do a Google search for. Instead of Default behavior, say something like Default behavior when you close an issue.
    • The headings (other than the page title) should be active. Instead of Configuring GDK, say something like Configure GDK.
    • Any task steps should be written as a numbered list.
    • If the content still needs to be edited for topic types, you can create a follow-up issue with the docs-technical-debt label.
• Review by assigned maintainer, who can always request/require the reviews above. Maintainer's review can occur before or after a technical writer review.