Doesn't warn about untyped captures in bindings files
It's easy to not specify a type for a capture in a bindings file. It'd be nice if Subplot could warn about that. Making it an error would be a breaking change, but having a linter for subplots would be nice.
$ subplot lint foo.subplot
foo.yaml: binding doesn't specify a type for the capture on line 12
...
A linter would in general be a nice addition to Subplot, I think.