Pull request #134: 4503 upstream conf

Merge in DNS/adguard-home-wiki from 4503-upstream-conf to master

Squashed commit of the following:

commit 1ba7ebc67b3b42a36abb861811306b4485ce785b
Author: Shared Content Manager account <translate@adguard.com>
Date:   Tue May 17 11:31:57 2022 +0300

    Configuration.md edited online with Bitbucket

commit ec7719acdd689dcfeb345d5832a819f67e8ba0ea
Author: Shared Content Manager account <translate@adguard.com>
Date:   Tue May 17 11:31:41 2022 +0300

    Configuration.md edited online with Bitbucket

commit dcc97786e1eb49c1d80732069a2455b2fe5f5dd5
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 16 16:05:46 2022 +0200

    4503 upstream conf

commit 2280824121afb4970b3b3c4af9a66ee2eae1b0f8
Author: Dimitry Kolyshev <dkolyshev@adguard.com>
Date:   Mon May 16 15:50:15 2022 +0200

    4503 upstream conf
Dimitry Kolyshev 2022-05-23 16:04:58 +03:00
parent 196e306489
commit 75bf461ad4

@ -84,6 +84,8 @@ Examples:
* `[/example.local/]1.1.1.1`: DNS upstream for specific domains, see below.
* `[/*.example.local/]1.1.1.1`: DNS upstream for specific subdomains, see below.
### <a href="#upstreams-for-domains" id="upstreams-for-domains" name="upstreams-for-domains">Specifying Upstreams For Domains</a>
You can specify upstreams that will be used for specific domains using the
@ -131,6 +133,10 @@ a configuration like this:
sends queries for `*.host.com` to `1.2.3.4` except for queries for
`*.www.host.com`, which are sent to `6.7.8.9`, which is the default upstream.
Since **v0.108.0-b.8** the wildcard `*` has a special meaning of "any subdomain",
so `--upstream=[/*.host.com/]1.2.3.4` will send queries for `*.host.com` to `1.2.3.4`,
but `host.com` will be forwarded to default upstreams.
#### Examples
* A configuration like:
@ -154,6 +160,17 @@ sends queries for `*.host.com` to `1.2.3.4` except for queries for
sends queries for `*.host.com` to `1.1.1.1:53` except for `*.maps.host.com`
which are sent to `8.8.8.8:53` along with all other queries.
* A configuration like:
```none
8.8.8.8:53
[/host.com/]1.1.1.1:53
[/*.host.com/]2.2.2.2:53
```
sends queries for `*.host.com` to `2.2.2.2:53` except for `host.com` queries
those are sent to `1.1.1.1:53`, but all other queries are sent to `8.8.8.8:53`.
### <a href="#upstreams-from-file" id="upstreams-from-file" name="upstreams-from-file">Loading Upstreams From File</a>
Using specific upstreams for some domains is a common way to accelerate internet