adguardhome: Implement initial package recipe

AdGuardHome is a network-wide ads and trackers blocking DNS server.
After installing it with opkg, start it like every service:
/etc/init.d/adguardhome start

In order to complete the installation vist http://{YOUR_ROUTERS_IP}:3000.

Then you can setup dnsmasq to forward DNS traffic to AdGuardHome:
uci -q delete dhcp.@dnsmasq[0].server
uci add_list dhcp.@dnsmasq[0].server=127.0.0.1#{PORT_SET_DURING_INSTALL}
uci set dhcp.@dnsmasq[0].noresolv=1
uci commit dhcp
/etc/init.d/dnsmasq restart

Signed-off-by: Dobroslaw Kijowski <dobo90@gmail.com>

net/adguardhome/files/adguardhome.init

@@ -0,0 +1,17 @@
+#!/bin/sh /etc/rc.common
+
+PROG=/usr/bin/AdGuardHome
+USE_PROCD=1
+
+# starts after network starts
+START=21
+# stops before networking stops
+STOP=89
+
+start_service() {
+  procd_open_instance
+  procd_set_param command "$PROG" -c /etc/adguardhome.yaml -w /tmp/adguardhome --no-check-update
+  procd_set_param stdout 1
+  procd_set_param stderr 1
+  procd_close_instance
+}