allow custom axios instance

[BilligsterUser]

This would allow users to do things like

import { setupAxios } from './axios';

setupAxios({ timeout: 1000 })

or

setupAxios({
	'httpAgent': new SocksProxyAgent(`socks5h://${torConfig.ip}:${torConfig.port}`),
	'httpsAgent': new SocksProxyAgent(`socks5h://${torConfig.ip}:${torConfig.port}`),
})