* Support generating bash completion
This patch adds subcommand to generate completion script for bash.
As an knative user, we would like to complete subcommands and
options rather than typing them.
* Adds docs about bash auto completion in README.md
This changeset adds auto-completion section in existing README.md
Suggested-by: Navid Shaikh <nshaikh@redhat.com>
Kenjiro Nakayama