convert.ps1

$files = Get-ChildItem -Recurse -Filter '*.json' -Path 'Users'
$delimit = '---'

foreach ($file in $files) {
    $yamlFileName = Join-Path $file.DirectoryName "$($file.BaseName).yaml"
    $content = Get-Content $file -Raw

    if ($content -match $delimit) {
        $yamlDocs = $content.split($delimit) | ForEach-Object { $_ | ConvertFrom-Json -Depth 5 | ConvertTo-Yaml }
        $yamlStr = $yamlDocs -join "$delimit`n"
    }
    else {
        $yamlStr = $content | ConvertFrom-Json -Depth 5 | ConvertTo-Yaml
    }

    $yamlStr | Out-File $yamlFileName -Force -Encoding utf8 -NoNewline
}