Add 'no help' output on help requests for unknown commands.
Add 'no help' output on help requests for unknown commands.

spark/particle-cli,kennethlimcp/particle-cli,kennethlimcp/particle-cli,spark/particle-cli,spark/particle-cli,spark/particle-cli,kennethlimcp/particle-cli,kennethlimcp/particle-cli,spark/particle-cli,kennethlimcp/particle-cli,kennethlimcp/particle-cli,spark/particle-cli