Pull request: 3457 fix service reload

Merge in DNS/adguard-home from 3457-darwin-svc-reload to master

Closes #3457.

Squashed commit of the following:

commit e3d6fbccf8373194360b6480e2d702ccd0ec7107
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Wed Aug 18 00:52:39 2021 +0300

    aghos: imp docs

commit 220d37ebc1e0c2e9ba37a34650bff1480bd2fcf6
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Aug 17 15:45:52 2021 +0300

    all: fix ps

internal/aghos/os_windows.go

@@ -4,8 +4,6 @@
 package aghos
 
 import (
-	"syscall"
-
 	"golang.org/x/sys/windows"
 )
 
@@ -34,10 +32,6 @@ func haveAdminRights() (bool, error) {
 	return true, nil
 }
 
-func sendProcessSignal(pid int, sig syscall.Signal) error {
-	return Unsupported("kill")
-}
-
 func isOpenWrt() (ok bool) {
 	return false
 }