feat: MarkX.ToString flexibility ( Fixes #35 )

Author: StartAutomating

Types/MarkX/ToString.ps1

@@ -1,2 +1,18 @@
+if ($args) {
+    $anyOutput = foreach ($arg in $args) {
+        $thisArg = $this.$arg
+        if ($thisArg) {
+            if ($thisArg.XHTML.InnerXML) {
+                "$($thisArg.XHTML.InnerXML)" + [Environment]::NewLine
+            } else {
+                "$thisArg"
+            }
+        }
+    }
+    if ($anyOutput) {
+        return $anyOutput -join [Environment]::NewLine
+    }    
+}
+
 if (-not $this.XML.XHTML) { return '' }
 return ("$($this.XML.XHTML.InnerXML)" + [Environment]::NewLine)