doc fixes
doc fixes


Former-commit-id: a8ea616fc27f7ae0ef8d1d5739d6fbce5a0cd48a [formerly 33720fc08e4592110b4dc9ce70cf786e5997b796]
Former-commit-id: 2a4eb4d9eba81aa14bbfc2e0c125145dfcfdedb3
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine