Extension method to turn a DataTable into a Markdown table

DataTable.AsMarkdownTable.cs

public static StringBuilder AsMarkdownTable(this DataTable source)
{
    StringBuilder sb = new StringBuilder();

    foreach (DataColumn column in source.Columns)
        sb.Append("|").Append(column.ColumnName.Trim());

    sb.AppendLine("|");

    for (int i = 0; i < source.Columns.Count; i++)
        sb.Append("|----");

    sb.AppendLine("|");

    foreach (DataRow row in source.Rows)
    {
        foreach (object val in row.ItemArray)
            sb.Append("|").Append(Convert.ToString(val).Trim());

        sb.AppendLine("|");
    }

    return sb;
}