Improve setup guide for AdguardHome running in Docker

### Prerequisites

- [X] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions) and found no answer

- [X] I have searched other issues and found no duplicates

- [X] I want to request a feature or enhancement and not ask a question

### The problem

Hello!
After successfully setting up AdGuardHome via the Docker installation on a Raspberry Pi, the setup guide states that the DNS server is available on these IP addresses:

The `172.17.0.2` IP address is the Docker virtual interface and is not exposed to other machines running on the same network as the Raspberry Pi.

### Proposed solution

* Clarify that the IP address for the Docker virtual interface should be used by clients on the same host
* Specify the machine's IP address for use by external clients on the same network

If there's something I'm missing, please let me know. I'm also happy to make this change (if it's valid).

### Alternatives considered and additional information

_No response_