[DOC] Add all six core gateway http/json api calls.
[DOC] Add all six core gateway http/json api calls.

whotooktwarden/gatewayd,Parkjeahwan/awegeeks,zealord/gatewayd,xdv/gatewayd,crazyquark/gatewayd,xdv/gatewayd,Parkjeahwan/awegeeks,whotooktwarden/gatewayd,zealord/gatewayd,crazyquark/gatewayd