Improve documentation

[gerrod3]

Updated small bits to better reflect what is current in 2026.

📜 Checklist

• Commits are cleanly separated with meaningful messages (simple features and bug fixes should be squashed to one commit)
• A changelog entry or entries has been added for any significant changes
• Follows the Pulp policy on AI Usage
• (For new features) - User documentation and test coverage has been added

See: Pull Request Walkthrough

[jobselko]

host.md also says that pull-through packages are stored as orphaned content, this is no longer true