Add support for Go templates

[bigjazzsound]

I would also like to see this get implemented.

Helm uses go templates inside yaml files. Unless the templates are quoted, the yaml parser does not know how to handle them. Hopefully it would be possible to inject go templates into these yaml files.

[amaanq]

This should be done by creating a gotmpl grammar and injecting it into this one.

[aryx]

maybe we should put special label when closing such issues, like wontfix, or something, otherwise when closing it like this it sounds like the issue was fixed, when really it's not.

[amaanq]

Ah right, we can use not planned