Feature Request: Allow reading vars/json from stdin

[pinpox]

Hi, if i'm not mistaken it is only possible to read template files from stdin but not json data to be used. I'd like to be able to do something like this, to read json from other commands:

curl https://example.com/something.json | gucci template-file.tmpl

[noqcks]

great idea. I would support any PRs of this nature

[rjshrjndrn]

I think more streamlined approach will be

curl https://example.com/something.json | gucci template-file.tmpl -f -

Else it'll be confusing whether the piped file is template or variable