Replace README.txt with README.md in the packager script
Replace README.txt with README.md in the packager script


Former-commit-id: 587fe1d8bb6e4ccbecb2ca087c27ae00edabf09f [formerly 4e10cded453c7ab78e2767f097e408bafa08715a] [formerly 4e10cded453c7ab78e2767f097e408bafa08715a [formerly 0dece9326bb6fa05a7a0ea65f07ab764c6530ecf]]
Former-commit-id: 09979b1add5d397d569be86a484c52a298a112bd
Former-commit-id: f502eba24cfa579bed3e5986cce007849727386f
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine