Adding template property. Expects string.

I haven't updated the `CHANGELOG.md` because it would cause a merge conflict with #17. Please merge that one in and I'll rebase master on this PR and update the `CHANGELOG.md` before we merge it in. Actually, I think the grunt build of this PR would conflict with the build of the other, so it doesn't make much of a difference, but I'd like to get these both in please :-)