Bind horizon init js after DOM Ready

This would change line 48 of _scripts.html from $(document).ready(horizon.init); to $(document).bind("ready", horizon.init); which would allow all JS executing on ready to execute before Horizon initializes. This was encountered as an issue when trying to execute additional javascript on a Workflow tab. The javascript is trying to build out a canvas that requires that the canvas not be hidden on the page during execution, however the Workflow js was executing first and hiding the div.