[feature] Custom generator classes

[terion-name]

Example usecase: I need to generate schema with different naming conventions (e.g. replicate Prisma1/OpenCRUD convention).

I can write custom generation class, but there is no way to pas it to parent generator without extending it and overriding. It would be great to have something like this:

class LegacyGenerator {...}
new Generator({generator: {legacy: LegacyGenerator}})

Also export current generation classes to be able to extend them

[AhmedElywa]

It's a good idea.
Also, If you can help, you can make a pull request.

[simonjoom]

i m not sure but my work might help:
i made a paljs working with prisma1 crud system using a moded version of nexus-plugin-prisma working with prisma3
#264

can be a start?