Support for Go text/html templates.

[oSethoum]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
like Goland has support for go templates, and autocompletion for structs inside templates.

Describe alternatives you've considered
I considered using goland but it's full IDE huge and not free.

Additional context
From Goland.
Add any other context or screenshots about the feature request here.

[suzmue]

The extension has some support for go templates already. Instructions for setting the language of your template files so that you get these features is available here and progress of the features can be tracked through issue #609.

Closing as a duplicate of #609