Add developer README.md to the release directory
Add developer README.md to the release directory

[#104919576]

cloudfoundry-incubator/lattice-release,cloudfoundry-incubator/lattice-release,cloudfoundry-incubator/lattice,cloudfoundry-incubator/lattice,cloudfoundry-incubator/lattice,cloudfoundry-incubator/lattice-release,pivotal-cf/micropcf,cloudfoundry-incubator/lattice-release,cloudfoundry-incubator/lattice,pivotal-cf/micropcf