TokenConfig generator tool for already deployed token contracts

[abhayks1]

• Make a command to generate token config. Create a tool that generates token config
  by providing the gateway contract address, origin chain endpoint and auxiliary chain endpoint.

• Get the possible contract address from the chain, ask user for the following:
  - name of config. This can be optional field. If user doesn't provide the name gateway address
  can be used for name of file.

    - path where token config needs to be created.
  
    - gateway contract address
  
    - Auxiliary chain id
  
    - Message bus, GatewayLib, MPP library addresses.
  
    - stake pool contract address.
  
    - redeem pool contract address.
  

• Update readme