Add guideline for dev DNS server

[ad-m]

With the deprecation of path-style URLs this year I think it's important to figure out how to make developing without path-style access as frictionless as possible.

@kherock in issue #624

In order to facilitate the configuration of the development environment, it is worth noting that in many cases it is sufficient to use DNS services such as xip.io to support host-based path which point to localhost. For example, using following domain bucketname.s3.127.0.0.1.xip.io., bucketname.s3.127.0.0.1.nip.io., bucketname.127-0-0-1.org.uk., bucketname.vcap.me. or bucketname.localhost.tv.

[kherock]

I didn't realize those services existed! That basically solves everything. I'm sure there will be some people asking about ways to avoid resolution for external services, so I'd like to also see if I can create some examples with docker-compose + network aliases.

[ad-m]

This is only required for local use. For a public service, you can trivially configure the corresponding willdcard DNS record yourself.

Everyone can also run a similar service on their own using own domain, because it does not require any special functionality of the DNS server. Then there is no need to rely on untrusted public services.

I understand that Docker makes it easier in terms of service discovery, but this seems to me another problem a little bit outside the application, but in the case of free resources worth documenting.