Initial work on the What's new in 2.3
Initial work on the What's new in 2.3


Former-commit-id: aaa543d43dcdfd9a22f143e6495e0112cd0e5772 [formerly 2341feb247e3aaa103fd33f89a25326bd2c57348]
Former-commit-id: 757c9914830978b9f24f2af08ee5fecbfc9e432d
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine