Consider removing the ES5 styleguide.

[goatslacker]

It's probably out of sync with the main styleguide and we should be promoting the latest and greatest rather than clinging onto JS from 10 years ago.

I therefore propose we deprecate the ES5 folder.

We can move it out of this repo or perhaps even just point to a commit which has the file if people would like to view it.

[ljharb]

Sure, that makes sense. (more 1 year than 10 years, since ES6 only came out a year ago :-p)

After I finish #936, I'll make a tag for ES5, and add a link to that in the main readme, and then delete the ES5 stuff in a separate commit.

[cmalard]

As ES6-7 is not working on the wild without using stuff like Babel, why be in such a hurry to remove it?

I'm not telling to keep it 10 years, but maybe to go a little slowly :-)

[lencioni]

The main reason I see is that we no longer write ES5 code at Airbnb, so it will continue to drift. Since it is still available in git history, it will still be referenceable, but we won't have the burden of needing to maintain it anymore.

[ljharb]

@cmalard our guide recommends using babel, so if you're not using babel, you're already not following it :-p