Use gitlab-ci to automatically generate documentation

Cherry-picked from develop-staging:

Various commits implementing build script and gitlab-ci
Add initial structure for documentation
mo_jsb_model_init.f90 is used as first example for ford documentation comments
019728b2 | Add option to dsl4jsb.py to not write header to target file "-n" or "--no-header" will
           not write the header with the hash to the pre-processed file
0d01464d | Adaptation for new version of ford documentation tool
           o New version fails on missing cdipio.inc, therefore put it in doc/include.

Adaptation for new version of ford documentation tool

New version fails on missing cdipio.inc, therefore put it in doc/include.

Cherry-picked from develop-staging@0d01464d