typedefs for typescript support

[HannesGitH]

Using this module with strict typescript is hard, and i need to open the docs/wiki for everything instead of using intellisense

a solution would be to have strong types / a types.d.ts file for typedefinitions

I might open a PR soon since i create the necessary types for my use anyway
edit: i wont create that since i've given up as i wont understand sdmx as quickly as i hoped (i just wanted to get the birth rates per month from the un data website, if someone could help me i'd create the type declarations)

[HannesGitH]

similar to this

declare module 'sdmx-rest' {

    type query = any; //TODO
    export function request(query: query, url: string): Promise<any>;


    type PredifinedServicesId = "BIS" | "ECB" | "ECB_S" | "EUROSTAT" | "OECD" | "OECD_S" | "SDMXGR" | "SDMXGR_S" | "UNICEF" | "WB" 
    type ServiceParams = PredifinedServicesId | { url: string, id: any?, name:any?, version: string?}
    type Service = any //TODO
    export function getService(ServiceParams): Service;

   //TODO

}