Fix xmldom DOMParser import

`xmldom` does not export `XMLDOMParser`, it exports `DOMParser` instead (https://www.npmjs.com/package/xmldom).

With TypeScript, the following error occurs, which breaks the build:

```
./node_modules/epubjs/src/section.js:100:18-34 - Error: export 'XMLDOMParser' (imported as 'XMLDOMSerializer') was not found in 'xmldom' (possible exports: DOMImplementation, DOMParser, XMLSerializer)
```

Making the correction manually in the local node_modules fixes this, but it's obviously not a longterm solution.

src/section.js

@@ -4,7 +4,7 @@ import Hook from "./utils/hook";
 import { sprint } from "./utils/core";
 import { replaceBase } from "./utils/replacements";
 import Request from "./utils/request";
-import { XMLDOMParser as XMLDOMSerializer } from "xmldom";
+import { DOMParser as XMLDOMSerializer } from "xmldom";
 
 /**
  * Represents a Section of the Book