Is your feature request related to a problem? Please describe.

I try to execute my first GET request and get this result:

I think the first-time-user experience could get improved here.

The hint to F12 vanishes soon, and I think accessing the error message via F12 is not a

🐣 Is your feature request related to a problem? Please describe.
We had a report in aiohttp-session (see aio-libs/aiohttp-session#574) that a user submitting a 'large' cookie had the cookie dropped by the receiving browser.

According to RFC 6265 - section 6.1:

General-use user agents SHOULD
provide each of the following minimum

Got has a very good coverage test-wise. Would be nice to port relevant tests that we're missing over to Ky.

Note: Not for https://github.com/sindresorhus/ky/blob/master/test/browser.js, but for everything else.

From time to time i see ppl using data instead of body which is wrong.
happened just recently in node-fetch/node-fetch#481 (comment)

how do you feel about adding a little warning message that can only appear once. (kinda like node reports that you are using experimental apis)

if ('data' in bodyInit && notWarned) {
  console.warn('use body i

A user often binds on a loopback port to serve internal use only requests. It is currently done with port() method:

Server
  .builder()
  .port(new InetSocketAddress("127.0.0.1", 8080))
  ...

It could be useful to have a shortcut method loopbackPort(int):

Server
  .builder()
  .loopbackPort(8080)
  .loopbackPort(9090, SessionProtocol.HTTP, SessionProtocol.