A simple and dirty dns server support match regex query name, get ip by execute command, etc.
Modify from dnsguide sample4.
```
USAGE:
dirty-dns [OPTIONS] --config-file
FLAGS: --help Prints help information -V, --version Prints version information
OPTIONS:
--config-file
```toml
[address]
'/w-(..jmjoy.top|..jmjoy.com)/' = "127.0.0.1" # regexp surround with //
'/x-(..jmjoy.top|..jmjoy.com)/' = "env(RUSTTESTIP)" # environment argument support
'/(..jmjoy.top|..jmjoy.com)/' = "echo 127.0.0.1
" # executeable command surround with ``
```