[AH-106] Updated the Oskari back end documentation.
[AH-106] Updated the Oskari back end documentation.

uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend,uhef/Oskari-Routing-frontend