refactor js

[jessicasalmon]

For two reasons:

1. the content of the homepage is currently completely reliant on the javascript powering the splash screen.
2. best practice is to load all content without javascript, and to use javascript to make progressive enhancements. In this way, a user who does not have javascript enabled on their browser or device can access the content, and users who do have javascript enabled can have a nicer experience (as opposed to one user having no experience and another user having a great experience).