Tag Helpers disabled in VS 2015

I am having trouble getting Tag Helpers enabled in my project.

Here is a summary of the project setup:

• VS 2015 RC Community Edition.
• Project.json reference: Microsoft.AspNet.Mvc": "6.0.0-beta4
• _GlobalImport.chtml has @addTagHelper"*,Microsoft.AspNet.Mvc.TagHelpers"

No build errors or warnings.

Must missing something, but I don't know what.

UPDATE:

Seems I am part of the way there. I added @addTagHelper "*, Microsoft.AspNet.Mvc.TagHelpers" to the _ViewStart.chtml. Razor is now processing things like <a asp-controller="Home" asp-action="Summary" title="Manage">TEST</a> as a link with a proper href attribute. However intellisense on not working.