[README] Update to reflect MP wraps various services.
[README] Update to reflect MP wraps various services.

artsy/metaphysics,mzikherman/metaphysics-1,mzikherman/metaphysics-1,artsy/metaphysics,broskoski/metaphysics,artsy/metaphysics,mzikherman/metaphysics-1,mzikherman/metaphysics-1,craigspaeth/metaphysics,craigspaeth/metaphysics