Force format of output

[squaremo]

jk transform and jk generate both have a --stdout argument, which will print all the objects to stdout. But this balks if the objects have different formats (either because the generation function gave them different formats, or because transform read them from files with different formats).

For the purpose eyeballing the results, it'd be good to be able to just force the format of everything to either YAML or JSON (these are the formats with a stream variation). In fact, this might be useful even when writing to files (and should change the extension!).

[squaremo]

This may be worth a modest RFC. Other things to cover:

• specifying input formats for files that don't have an extension
• ?