Improve typings

[djflex68]

Hello,

I'm wondering if there is a way to improve the typings definition by having the context variable being typed :

export interface ResultFunction<ResulType> {
    (root: any, args: any, context: any, info: any): Promise<ResulType> | ResulType | void;
}

becomes

export interface ResultFunction<ResulType, ContextType> {
    (root: any, args: any, context: ContextType, info: any): Promise<ResulType> | ResulType | void;
}

The idea behind that is that if we make some modifications on the context object (like adding new properties that would be needed by the next resolver in the pipe), we would then be able to retrieve a fully typed variable in the next resolver, instead of any.
In a perfect world, each resolver context type should augment the previous one, so that the last resolver gets a merged type of all added properties.

Thanks

[thebigredgeek]

#67