Add a FAQ about #3568 [skip ci]
Add a FAQ about #3568 [skip ci]


Former-commit-id: b85d75a373ab9165f01e778b7ef3581bf4fdf532 [formerly fc0243036ddcfd6b2490cfa2ef71f3b9d7af9522]
Former-commit-id: bb77b00e0445de3c014ab82c90fb4b23f4db29f0
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine