Documentation update for me.org

[ccarouge]

The current instructions for me.org in the User Guide are erroneous. They don't use the correct benchmarks and they request to change the model profile for each benchcab run when we should only have 1 CABLE profile. All other information about the realisations should be given within the model output.

Also, the User Guide section needs some information about using the automation via the API. It has been added to the config options page but not the "tutorial".