Helper for building markdown docs from PowerShell Command Help.

• Add-HelpDocText Return a markdown formatted text.
• Add-ModuleCommand Generate a Markdown list of the commands in the module and their summary.
• Add-ModuleProperty Return a markdown formatted value for the given property.
• Get-HelpCommandData A short one-line action-based description, e.g. 'Tests if a function is valid'
• Get-HelpModuleData Returns an object representation of the help available for the given module.
• New-HelpDoc Returns an empty HelpModuleReadme object.
• Out-HelpDoc Output the Markdown formatted HelpDoc.