[Feature Request] Note which options are required

[lorensr]

Is your feature request related to a problem? Please describe.

When I run this, I'd like to know

• whether the batch job started (it didn't)
• if not, how to get it to start (add rest of required options)

$ tctl batch start --query "ExecutionStatus != 'foo'" --batch-type terminate --yes

NAME:
   tctl batch start - Start a batch operation job

USAGE:
   tctl batch start [command options] [arguments...]

OPTIONS:
   --query value, -q value          Query to get workflows for being executed this batch operation
   --reason value, -r value         Reason to run this batch job
   --batch-type value, --bt value   Types supported: terminate,cancel,signal
   --signal-name value, --sn value  Required for batch signal
   --input value, -i value          Optional input of signal
   --rps value                      RPS of processing (default: 50)
   --yes                            Optional flag to disable confirmation prompt (default: false)
   --help, -h                       show help (default: false)

Describe the solution you'd like

• whether the batch job started (it didn't)

perhaps it is universally enough understood that printing usage means the command didn't work?

if not, how to get it to start (add rest of required options)

• under USAGE and/or OPTIONS, denote which are required or which are optional. here is one convention: https://stackoverflow.com/a/21503966/627729
• when entering a command without sufficient options, print the missing ones:

$ tctl batch start --query "ExecutionStatus != 'foo'" --batch-type terminate --yes

Missing required options:

   --reason value, -r value         Reason to run this batch job