Switch build from 'Publish-Module' to 'Publish-PSResource' offered by module 'PSResourceGet'

[ddemeyer]

Problem...
Documentation and RWS Community blog post already hinted that Microsoft is switching from Install-Module to Install-PSResource.

In turn we also need to switch from Publish-Module to Publish-PSResource for our automated build and help texts. Main advantage is that PowerShellGet 3.0 does not take a dependency on OneGet, NuGet or any other package provider therefore simplifying the codebase. This means that repositories like AWS

Actions...

• Check if PSResourceGet is available on the Github Actions PowerShell session in use
• Adapt continuous-integration.yml for the actual PSGallery publish of release/prerelease
• Adapt continuous-integration.yml for the help text on non-public repositories
• Check help markdown pages