Added condition for :update after commit & rescue if record NotFound

[rndev15]

Hey guys
I just added readme condition for such case:
Instance of article exists, persisted, and published so successfully indexed. Then, if you make it unpublished, according to current example it will not be indexed, because

self.published? == true

I've added condition to delete document if it's non-published, and update if published. In case document was published (created), then deleted (on update hook), and then published again, __elasticsearch__.update_document will create a new document.
Second point is exception handling - when gem trying to delete non-existing document, it throws Elasticsearch::Transport::Transport::Errors::NotFound. I've just added rescue for it.

Thank you.

[karmi]

Hi @romkaspb , sorry for the long silence here! I've read through the patch and both additions do make sense, thanks! Particularly the check for NotFound is useful for somebody copy&pasting code :)

The CLA check is red, would be so kind to sign the contributor agreement? I understand this is a small change to documentation, but it just makes all the administration around code changes easier.

Also, if you'd have a bit more time, would you be able to split the commit into two? These are unrelated changes and I had to squint for a while until I have realized the patch touches two different parts of the codebase :) It's not required by any means, I can do that myself during merging, or keep it as it is.

[rndev15]

Hi @karmi!
Sorry for much more long silence. I think I've missed notification somewhere in my mailbox. :)
Just signed contributor agreement and splitter PR to different commits.
Sorry for my poor english.

Thank you!

[estolfo]

Thanks @romkaspb !