For unsupported Types, fall back on `encoding/json`?

[pquerna]

Right now its hard to use megajson, because for types it doesn't understand, it just leaves an empty space in the generate code :8ball:

I'd vote for in any case that megajson can't generate more specialized code, for it to fall back on encoding/json, so that code is still functional, even if that specific path isn't fully-megaized.

[benbjohnson]

@pquerna The megajson encoder/decoder needs a refactor but I've been holding off because the templating is a PITA for doing codegen. I'm going to swap out the templates out for ego templates which should make it a lot easier to support all types.

:+1: for using megaized in your issue. :)

[dropwhile]

I would also love this :+1: