Add examples

[justinwoo]

Maybe we should add examples like in other libraries like https://github.com/purescript/purescript-foreign? I realize this could be a total pain when introducing changes in the future, but I wouldn't mind being asked to update them.

I have some basic-ish examples in https://github.com/justinwoo/simple-record-foreign-generic-demo and https://github.com/justinwoo/purescript-howto-foreign-generic at least that I could work on porting to whatever format is most convenient.

[justinwoo]

Err, yeah, related to #17 definitely I guess, since either (or both) could be good.

[paf31]

Perhaps we could just link to you existing repos/egghead lesson?

[justinwoo]

Ha! Could work, but I think the Egghead lesson might eventually go paid-only or out of date and my example repos could very easily get stale, unless we set something up to somehow run some tests on commits to this project?...

[paf31]

True - well either way works. I'll gladly take a PR.