Don't trigger PSAvoidUsingWriteHost for functions using the Show verb

Per, community rule [out-01](https://www.penflip.com/powershellorg/the-community-book-of-powershell-practices/blob/master/out-01-dont-use-write-host-unless-writing-to-the-host-is-all-you-want-to-do.txt) Write-Host should be allowed inside functions starting with the Show verb
