shadow cljs fix

[rksm]

I believe that this fixes #15. I'll test this some and would invite others testing as well.

[arichiardi]

LGTM - haven't tried it though

[bbatsov]

Looks good to me as well - at the very least this is no longer going to blow up with shadow, even if it turns out the completion doesn't work properly. I guess @thheller can potentially confirm if we're using the right shadow-cljs API right now.

Other than this - seems you've reflowed the entire README (I see most like breaks are gone), so it's hard to understand what are the documentation changes, but I'll assume those are fine.

I was thinking it will be nice if there was a section in the docs about hacking on suitable - should be useful to potential contributors.

[bbatsov]

One more thing - if this API didn't exist before shadow 2.10, we should probably guard against this and just return an empty list of candidates.

[thheller]

LGTM. I'll make sure that cljs-eval API fn stays alive and functional.

[rksm]

@bbatsov the pure diff of README.md, only minor changes. Sorry the line breaks did bother me.

[bbatsov]

I saw you already cut 0.4, so I guess it's time to merge this branch. Big thanks for working on this!