doc/Mac: add a missing link
doc/Mac: add a missing link


Former-commit-id: 0c7cdddf8f306a2e2faa2092eb3a5e7af1c29d45 [formerly 5ff8bf758f7bc7d6d9d09f5641a4b909332859d0]
Former-commit-id: 33b7802526164283f45a11f3b5d93ba1e3d7dfa8
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine