dom-parsing/XMLSerializer.ts: fix a typo in a comment (#133)

The value ‘true’ is passed to require well-formed output, not ‘false’ as
stated in the comment.

Author: rrthomas

src/dom-parsing/XMLSerializer.ts

@@ -48,7 +48,7 @@ export default class XMLSerializer {
 export function serializeToWellFormedString(root: Node): string {
 	root = asObject(root, Node);
 
-	// Produce an XML serialization of root passing a value of false for the require well-formed
+	// Produce an XML serialization of root passing a value of true for the require well-formed
 	// parameter, and return the result.
 	const result: string[] = [];
 	produceXmlSerialization(root, true, result);