{currency}: Search countries by currency

curl 'https://restcountries.com/v3.1/currency/usd'

import requests

resp = requests.get("https://restcountries.com/v3.1/currency/usd")
data = resp.json()

import zingu_apis

api = zingu_apis.api("world-countries")
result = api.fetch("currency/{currency}")

for item in result:
    print(item)

const resp = await fetch("https://restcountries.com/v3.1/currency/usd");
const data = await resp.json();