I have VS2015 Enterprise (ver 14.0.25431.01 Update 3) installed and I’ve added the Microsoft Dynamics 365 Developer Toolkit (ver 1.3.2000.9032) via the “Extensions and Updates” dialog.
The “Project New” dialog allows me to create a “Dynamics 365 Package”, and I can connect to our on-premises Dynamics CRM installation just fine.
However, when I right-click on “WebResources” folder and “Add > New Item”, there are no CRM templates available, so there is no way from the IDE to add new HTML, JS, CSS, etc., files to the project.