Documentation for "--release" option to init is incorrect

[awrichar]

When running ff help init, you see:

  -r, --release string                Select the FireFly release version to use. Options are: [stable head alpha beta rc] (default "latest")

This is incorrect - this field does not take channel options like stable head alpha beta rc. It takes a specific Docker tag name, but it does default to latest.

[tobigiwa]

@awrichar Am assuming this specific docker tags are the same tags on the github repo?https://github.com/hyperledger/firefly/tags