module CmAdmin::Models::DslMethod

def custom_action(name: nil, verb: nil, layout: nil, partial: nil, path: nil, &block)

end
end
end
end
Code for action here...
def user_submit
custom_action name: 'submit', verb: 'post', path: ':id/submit' do
cm_admin do
class User < ApplicationRecord
eg
Custom actions 
def custom_action(name: nil, verb: nil, layout: nil, partial: nil, path: nil, &block)
  @available_actions << CmAdmin::Models::Action.new(name: name, verb: verb, layout: layout, partial: partial, path: path)
  self.class.class_eval(&block)
end