No, it's just this: http://isotope.metafizzy.co/docs/hash-history-jquery-bbq.html This is already the full code.
However, you don't have HTML version of a filter but in project-loop.php you have the following instead:
Instead of using
jQuery.param() you'll probably need PHP's http://php.net/manual/en/function.urlencode.php
Secondly, in project-script.php you'll find Isotope initialized on line 419 and from that point onwards you can implement your script to update Isotope when URL changes. I think that even class naming is the same so perhaps copy/paste of the code from the documentation above will work.
"I told my customer that this would be a simple task and done quickly."
Yes, it is fortunately - 30 minutes should be enough to complete this. I hope that my above information clarifies this a little bit more.
Although this is a nice feature we decided not to implement it in the main package. We don't want to complicate an URL too much. Isotope doesn't implement it anywhere except that single demo either. We'd like to keep the URL clean and simple. Not everyone would be fine with having permanent hash URLs. Instead, we'll leave this feature as an option with implementation description on the forum.
All suggestions like that are obviously a subject to discussion but in this case both versions have advantages and disadvantages and I think that it's better if we just leave it like most Isotope demos (no URL updating for not permanent URLs).