Add support for unknown tags

[halljson]

I needed this code change to get cartridge working:

Would prefer to merge this into master (rather than forking this repo) so that everyone can use it!

(Tried pushing my branch, but:)

Please make sure you have the correct access rights
and the repository exists.

[tdavis]

Would it be better to offer another arity that let callers set options like :default? What about internal use of read-response-from-disk; is it principally used elsewhere we should consider extending the option?

You can fork the repository and open a PR from your fork. Proposing a patch with an image is... creative.

[halljson]

you can open a PR from your fork.

TIL! (hence my lazy/creative solution)

Thanks, I'll put in that PR shortly.