Update documentation

[MarkEWaite]

Update documentation

Several improvements to the documentation, including:

• Fix spelling error in heading
• Remove badges, not used in most other docs
• Minor documentation phrasing changes
• Replace wiki reference with in-page link
• Link to Javadoc and reduce example text width
• Remove outdated changelog, link to tagged version
• Update screenshots with Jenkins 2.401.1

Testing done

Reviewed from GitHub view.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue