CLI: Add a way to add a worker to Kubernetes

[A-Harby]

Is your feature request related to a problem? Please describe

Add a way to add a worker to Kubernetes master using the TFCMD, The only possible way to add workers is to create a new Kubernetes master with workers.

Describe the solution you'd like

A better option is to add a way to add a worker to an already created master.

[Eslam-Nawara]

there's a way to add a worker to kubernetes cluster, check this example here

[A-Harby]

there's a way to add a worker to kubernetes cluster, check this example here

Nice, Can we just mention how-to on the docs?

[Eslam-Nawara]

WIP

• added update command with subcommands to add/delete workers

will need to add documentation to the new command