Use let and const for docs?

[jxu]

Does plotly assume ES6 support? Should let and const be used in the docs for modern practice because var has some tricky pitfalls?

[nicolaskruchten]

We do not assume ES6 although your suggestion is probably a good one. We would accept a PR that made this change :)

[jxu]

I don't know if the docs should use let if we cannot guarantee ES6 support. The change would affect pretty much every single page which is a lot, though I noticed some code already uses ES6 arrow functions so those have to have ES6 already.

[nicolaskruchten]

We'd probably accept some big standardizing PRs yup.