Add supported Node.js versions in latest Docs

[PatrickHeneise]

• Version: 6

Search engines usually show the latest docs for Node.js. Today I had the frustrating task to debug why my Buffer.from(string, encoding) function worked perfectly fine on my developer machine but threw a TypeError 'binary' is not a function. It took me a while to realise I'm running Node 4 LTS on staging and of course Node 6 on the dev machine and that Buffer.from is not working in 4 LTS, but already deprecated in 6. Worse is that Buffer.from() should have thrown the non-existing function error, as it's not listed in the v4 docs.

I think it would be great help to have the supported versions for each function in the latest documentation to see when a function has been introduced and when it gets deprecated, best with colours ranging from green, orange and red (just an idea), to indicate right away the status.

[cjihrig]

cc: @nodejs/documentation

[jasnell]

There was a previous effort to do this that stalled out because the person working on it ended up getting busy on other work. Would love to see this revisited.

[addaleax]

There’s #3713 and the doctool support PR in #3867. I’ve asked to rebase the latter one because I’d love to work on this, but no response so far.

[addaleax]

Closing this as a duplicate of #3713, and I’m working on this in #6495.