Usage description incorrect

[myrho]

Hi! Thanks for adding support for risky requests. However, the feature does not work as described in the usage message.

  --effect-types                     Which kind of APIs to generate, the options are:
                                      - cmd: input -> Cmd msg
                                      - riskycmd: as above, but using Http.riskyRequest
                                      - task: input -> Task Http.Error msg
                                      - riskytask: as above, but using Http.riskyRequest
                                      - backendtask: for dillonkearns/elm-pages

The command actually works with cmdrisky and taskrisky instead.