To use the embed tag, you'll have to base64 encode your HTML or PDF file. Base64 encoding can be used in conjunction with an XML file to embed binary data. You'll have to find a way to encode your pdf into base64, but there are online tools available -- check out, for example, http://www.google.ca/search?hl=en&q=bas ... arch&meta=
The base64 encoded text (which looks like a stream of characters, like PGxpPjxCPlc8Zm9udCBzaXplPS0xPkVJTkVSPC9mb250PjwvQj4sIEU ... etc.) goes between the <embed> tags. So you would have something like
<embed encoding="base64" filename="my_file.pdf" mime_type="application/pdf">PGxpPjxCPlc8Zm9udCBzaXplPS0xPkVJTkVSPC9mb250PjwvQj4sIEU...(and so on)...</embed>
Where the character stream is actually your base64-encoded PDF.