Create new version for NorESM 2.dev

[gold2718]

As progress is made towards the next version of NorESM based on the NUOPC architecture, a new version of the documentation is needed to correctly document the places where the structure of the code or use of the model is different.

[TomasTorsvik]

@gold2718 @mvertens @adagj @DirkOlivie
Should we make a noresm2.3 branch now? I suppose we want to branch off from noresm2.1?

[mvertens]

@TomasTorsvik - yes - that makes sense to me. Thanks for bringing this up.

[TomasTorsvik]

@gold2718 - I see you already have a noresm2.3 branch in your fork. Would you like to push this to the main repository as a starting point?

[gold2718]

@gold2718 - I see you already have a noresm2.3 branch in your fork. Would you like to push this to the main repository as a starting point?

Yes. Let me just add a few items and I will push it.