Script comment-based help

<#

.SYNOPSIS
    Reads a CSV file and filters it.

.DESCRIPTION
    The ReadUsersCsv.ps1 script reads a CSV file and filters it on the 'UserName' column.

.PARAMETER Path
    Specifies the path of the CSV input file.

.INPUTS
    None. You cannot pipe objects to ReadUsersCsv.ps1.

.OUTPUTS
    None. ReadUsersCsv.ps1 does not generate any output.

.EXAMPLE
    C:\PS> .\ReadUsersCsv.ps1 -Path C:\Temp\Users.csv -UserName j.doe

#>
Param
(
    [Parameter(Mandatory=$true,ValueFromPipeline=$false)]
    [System.String]
    $Path,
    [Parameter(Mandatory=$true,ValueFromPipeline=$false)]
    [System.String]
    $UserName
)

Import-Csv -Path $Path | Where-Object -FilterScript {$_.UserName -eq $UserName}