Move 5.0 moniker to the top (#20098)

* Move 5.0 moniker to the top

* Move 5.0 moniker to the top

* Update aspnetcore/fundamentals/host/generic-host.md

Co-authored-by: Luke Latham <llatham@aquent.com>

* Apply suggestions from code review

Co-authored-by: Scott Addie <10702007+scottaddie@users.noreply.github.com>

Co-authored-by: Luke Latham <llatham@aquent.com>
Co-authored-by: Scott Addie <10702007+scottaddie@users.noreply.github.com>

Author: 3 people