CLI tool

I am thinking about creating a CLI tool - its features, capabilities and usefulness. Few ideas are in my head right now:

Basic:
- `init` command to create base configured app skeleton from boilerplate repo
- `init` command with more detailed config (folder per type/feature, etc.)
- automatic generation of resolver and type classes and files
- automatic generation of CRUD resolvers from object type classes

Advanced:
- types generation - create a template to generate complicated derived types from model, ex. filter or where inputs
- SDL converter - generate TypeGraphQL project with types, args, input and resolvers based on `schema.gql` file with SDL

:speech_balloon: Other proposals:
- integrate with [typeorm-model-generator](https://github.com/Kononnable/typeorm-model-generator) or other way for generatic object types from db (@omatrot)
- ~exporting the graphql schema from classes (@omatrot)~ done in #170

The issue names no implementation files, tests, or entry points and lists several possible CLI features. Start by reviewing the existing TypeGraphQL project structure and related issue #170, then narrow the proposal to one agreed command or capability with a defined completion criterion.

Written by the indexing model from the issue text.