Add query string values to url.
(addition: String | Object) => (url: string) => string
import qsAdd from 'qs-add';
qsAdd({a: `aa`})(`/foo/bar`);// /foo/bar?a=aa
qsAdd(`a=aa`)(`/foo/bar?a=x`);// /foo/bar?a=aa
qsAdd({a: `aa`})(`https://user:psw@sub.example.com:3000/foo/bar?query=string#hash`);
// https://user:psw@sub.example.com:3000/foo/bar?query=string&a=aa#hash