[Feature proposal] Configuration files using cosmiconfig

[loicplaire]

This is not an issue report but a proposal for the implementation of configuration files.

What would you think of adding cosmiconfig so that we could configure graphql-faker using either:

• a package.json property
• a JSON or YAML, extensionless "rc file"
• an "rc file" with the extensions .json, .yaml, or .yml.
• a .config.js CommonJS module

In my use case, I see the benefits of using a .config.js file so that I can use my project config file to avoid duplication e.g for the extend url.

Let me know if this is something you would consider for graphql-faker and I would be happy to implement it!

[IvanGoncharov]

@loicplaire I don't think it's very critical feature for Faker but if it fits in dozen lines I don't see why not 👍
Please keep it simple: sync code, config format that emulates yargs output, etc.
Also, don't forget to update README.md.