[IDEA] Add custom generator support

[pierre-H]

Hello,

It would be great to add an option to support custom generator with custom templates.

For example : I often use Semantic UI for React in TypeScript in multiples projects. So I'd like to create my own generator with all templates needed and to use it like this generate-api-platform-client --generator=reactSemanticTs.

I don't know what's the best way to support this (specifically how to not overwrite custom generators when updating the client-generator). Does someone have an idea ?

Thank you for your great work !

[soyuka]

You can use a custom directory for templates already #32. Not sure how we could allow custom generators because they are really specific. Feel free to contribute with your own generator.