Added embed link to the generated asciicast page. In the rare instance t...

Embed and copy HTML link added to asciicast page. Originally attempted to add this functionality via the web workers, but ran into issues. Instead decided to add it into the bound click function of our link, which pulls height and width from the asciicast. In the rare instance that a user clicks on that link before the asciicast movie is initialized, the height and width will come back null. It's extremely unlikely and the user would need to have some fast hands. 

This should close #67.