Add list of supported Node versions

[crandmck]

We should document which versions of Node that we test against and support.

[hacksparrow]

@crandmck maybe we should use the changelog file on the website for this?

[crandmck]

Yes, it would make sense to specify which Node versions a given release was tested against.

In addition, we should provide the list of supported Node versions of the current (latest) version of Express in a "Prerequisites" section in http://expressjs.com/en/starter/installing.html. Currently, it only says

Assuming you’ve already installed Node.js, ...

But we should clarify which version of Node.js you must install. Note: Although we may expect that it "should work" for many different versions, it's important to clarify which versions of Node are actually tested for a current release. That's what really matters to enterprise users.

[dougwilson]

I agree, all good points here.

[crandmck]

Closed in favor of #1478