health: Health check endpoint

curl 'https://kroki.io/health'

import requests

resp = requests.get("https://kroki.io/health")
data = resp.json()

import zingu_apis

api = zingu_apis.api("kroki")
result = api.fetch("health")

for item in result:
    print(item)

const resp = await fetch("https://kroki.io/health");
const data = await resp.json();