update README with Watson Tone setup instructions

[cmluciano]

I have not found instructions for setting up Tone within IBM cloud. Detailed instructions should be added to the v2 README or a consolidated README (at the root repo level).

[duglin]

ping @linsun

[linsun]

FYI

bx service create tone_analyzer lite my-tone-analyzer-service
bx service key-create my-tone-analyzer-service myKey
bx service key-show my-tone-analyzer-service myKey

The way i did it is to copy the user/pwd into the py code but I would prefer us to leverage the service binding provided in armada in kube 101 if we can.

[duglin]

ping @jberkhahn - this would be a good tie-in with svc-cat when/if things are ready. I think you can even reach it from an ICP install if we manage the keys manually. Ugly, but something we should discuss.