Debug templating/alternate files

[indigoviolet]

Is your feature request related to a problem? Please describe.

I'm frustrated when templating doesn't lead to the expected outcome, sometimes due to small typos in template syntax.

Describe the solution you'd like

A command like yadm template <template file> --verbose which displays detected templates and the context being passed to them.

For non-default engines, perhaps show the templating command.

Describe alternatives you've considered

Additional context

[Add any other context or screenshots about the feature request here.]