Everything looks good. The only change that you need to make is to load the jQuery before you load the img-filter.js. Also, you should only load one version of the foundation.js. You are loading in version 5 just after loading in jQuery and then the newer 6.6.3 after the foundation script initialization. If you want to use the newer version, move the CDN
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/foundation/6.6.3/js/foundation.min.js"></script>
before the initialization script
<script> $(document).foundation(); </script>
and delete
<script src="js/foundation.min.js"></script>
Then switch the order of the jQuery load
<script src="js/vendor/jquery.js"></script>
and your script
<script type="text/javascript" src="js/img-filter.js"></script>
Let me know if it works or if you need more help.
Bob