Philo

Right now, there's no way to track what variables an embedded template expects/supports. It would be useful someday to be able to give users the option of setting the kwargs for an embed - when using something like the js feature proposed in #149, for instance - and letting them know what the options were. Users might not guess that full=1 could do anything, let alone make an image full-width - or display a full caption - or whatever it might do.

I don't know yet what the format for this should be. Perhaps something like: {% embedvar "full" "Makes the image full-size" %}.
There should be no option for using context variables.