v0.7.0 (21-02-2018) support for V10.4
As of v0.7.0 code templates will work on V10.4, probably even in earlier versions but I need to check that.
For pre V11 a notebook approach is used instead of an AttachedCell
based menu. To enable attached cell method in earlier versions you can run
CurrentValue[$FrontEnd, {TaggingRules, "DevTools", "MenuMethod"}] = "Cell" (*or "Notebook" *)
but FE crashed for me once or twice and I was not able to reproduce circumstances so do it on your own risk.