doc: add HTTP working group
doc: add HTTP working group

Charter for the HTTP Working Group

PR-URL: https://github.com/nodejs/node/pull/3919
Reviewed-By: Colin Ihrig <838f779c91673db29b8572ea3f54d191d3878ae2@gmail.com>
Reviewed-By: Brian White <d8bbf19083844493ef08581d1c38fbc50ba5d18b@mscdex.net>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node