IGC help text changes

[mjperrins]

The following possible improvements to the CLI text changes could be made.

• Top level title maybe rename to `IBM Garage Cloud Native Toolkit CLI
• Does igc build work if not remove the function
• igc dashboard change to Open the Developer Dashboard in ....
• remove the igc launch-tools functionality or deprecate it for future release title is wrong as well
• Add URL to git org when igc --help used list some more links to Dev Docs
• igc login what does it do ? if redundant deprecate

Usage: igc <command> [args]

Commands:
  igc build                  Build the image and push it into the IBM Cloud
                             registry
  igc create-webhook         Create a git webhook for a given Jenkins pipeline
  igc credentials            Lists the urls and credentials for the tools
                             deployed to the cluster
  igc dashboard              Open the dashboard url in the default browser
  igc deploy                 Deploy an image from the IBM Cloud registry into a
                             kubernetes cluster
  igc enable                 Enable the current repository with pipeline logic
  igc endpoints              List the current ingress hosts for deployed apps in
                             a namespace [aliases: ingress, endpoint, ingresses]
  igc generate-token         Generate a Jenkins api token
  igc git-secret [name]      Create a kubernetes secret that contains the url,
                             username, and personal access token for a git repo
  igc jenkins-auth           Generate a Jenkins api token and register it as
                             kubernetes secret
  igc launch-tools           Launch the IBM Garage for Cloud tools image
                             connected to the current directory
  igc login                  Log in using the ibmcloud cli, optionally configure
                             the cluster, and optionally runs a command
  igc namespace [namespace]  Create a namespace (if it doesn't exist) and
                             prepare it with the necessary configuration
  igc pipeline               Register a pipeline for the current code repository
  igc tool-config            Create the config map and secret for a tool
                             configured in the environment
  igc vlan                   Print out the vlan values
  igc yq <command>

Options:
  --version  Show version number                                       [boolean]
  --help     Show help                                                 [boolean]

Not enough non-option arguments: got 0, need at least 1