please mention AtExit in the documentation

[kapouer]

Hi,
it would be nice to have AtExit mentioned in
https://github.com/joyent/node/blob/master/doc/api/addons.markdown

It would save developers a lot of time ;|

[indutny]

Yeah, it probably should be! Would you please mind submitting a PR for this? ;)

Submitted pull request to address this issue.
#8461

[jasnell]

Closing since the PR was closed and never landed.