Make 'frontendProject' in 'nx-electron:make' optional

[lailo]

Is your feature request related to a problem? Please describe. I'm building an app that doesn't require a UI besides the try menu but the frontendProject configuration in the project.json for the nx-electron:make requires to add a frontend app name.

Describe the solution you'd like Make the frontendProject configuration in the nx-electron:make optional.

Describe alternatives you've considered Instead of having a string and making it optional, we could have a list where you could leave empty or add multiple frontend app names.

Additional context No additional context.