Close Cerebro after copying to clipboard

[tiagoamaro]

Hi @KELiON,

First, thank you again for Cerebro and its awesome plugins 🎉!

I've been using a lot the emoj plugin, and noticed something that bothered me (a lot): it doesn't close after I click the desired emoji!

This PR aims to implement the following behavior:

• User searches emoji
• She/He clicks on the desired emoji
• Cerebro hides and emoji is on her/his clipboard

If you agree to merge this PR, do you want me to append a new version so you can publish it to NPM?

Thanks!

Also, there's no keyboard navigation, but that's for another PR. It's less bothering than Cerebro not closing after an emoji being selected.

[KELiON]

@tiagoamaro great, thanks! I'll bump the version by my own right now