Parameters key
Plans accept parameters in the parameters key. The value of
      parameters is a map, where each key is the name of a parameter and the value
    is a map describing the parameter.
Parameter values can be referenced from steps as variables.
Parameters use these fields, which are all optional:
- type: Specify a valid Puppet data type. The plan fails if the value supplied to the parameter does not match the defined type. If you do not specify a data type, this field defaults to- Any.
- default: Specify a default value to use if no specific value is supplied to the parameter. This can be empty.
- description: A description of the parameter. This can be empty.
For example, this plan accepts a load_balancer name as a string, two sets
        of nodes called frontends and backends, and a
          version string: 
parameters:
  # A simple parameter definition doesn't need a type or description
  load_balancer:
  frontends:
    type: TargetSpec
    description: "The frontend web servers"
  backends:
    type: TargetSpec
    description: "The backend application servers"
  version:
    type: String
    description: "The new application version to deploy"
                                        





