Add deployment type documentation

 - Modify DeploymentType to contain `documentation` field containing markdown documentation
 - Add deploy type documentation
 - Special case the magenta-lib/types documentation page to dynamically render the deployment types
 - Modify Param to take implicit instance of ParamRegister supplied by DeploymentType trait and used to gather the list of Params
 - Modify Param to contain methods to make default logic easier to understand
 - Add documentation field to Param
 - Document parameters of autoscaling deployment type