Add HelpUri to functions

[JohnRoos]

Describe the solution you'd like
Since we have all the documentation as markdown we should add HelpUri for each function which would point to the markdown file for that function. In that way its possible to use the -Online parameter for Get-Help.

Example:

function Build-Bicep {
    [CmdletBinding(DefaultParameterSetName = 'Default',
        SupportsShouldProcess,
        HelpUri = 'https://github.com/StefanIvemo/BicepPowerShell/blob/v1.4.2/Docs/Help/Build-Bicep.md')]
    ...
}

However, this should be release-specific, so we should not add a generic Url. It should be for the version installed (as in the example above).

[egullbrandsson]

I'll add a script to automatically do this and then we can re-use it for a GitHub action.