Added missing documentation for mget/mget_decoded.
Added missing documentation for mget/mget_decoded.


Former-commit-id: 620407f0b732d8ebbd865bf0bca4aeefc69ecc22 [formerly f2e2198da25c4a6f1603918f4fb31f57894a777f]
Former-commit-id: ec6fcfef976203048de71d704f7e2a89fb4d506e
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine