Do not use .local for unicast DNS examples

Please do not use ``.local`` domain for any unicast DNS examples. Only examples worthy using that domain is example of blocked forwarding. But README.md uses it do direct a domain to local resolver.

``.local`` should be only for [Multicast DNS](https://www.rfc-editor.org/rfc/rfc6762.html) and nothing else.

Alternatives:
- use ``home.arpa``, [RFC 8375](https://www.rfc-editor.org/rfc/rfc8375.html)
- use ``example.net``, just for similar purposes special domain