src/New-DocumentType.psm1

<#
.SYNOPSIS
    Creates a new document type declaration.
.INPUTS
    The value of the document type.
.OUTPUTS
    The rendered document type declaration.
#>

function New-HtmlDocumentType {
    [Alias("doctype")]
    [CmdletBinding()]
    [OutputType([string])]
    param (
        # The value of the document type.
        [Parameter(Position = 0, ValueFromPipeline)]
        [string] $Value = "html"
    )

    process {
        "<!doctype $([string]::IsNullOrWhiteSpace($Value) ? "html" : $Value)>"
    }
}