Add installation script

Add wireguard iptables rules

installers/install_feature_firewall.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+#
+# RaspAP feature installation: Firewall
+# to be sources by the RaspAP installer script
+# Author: @zbchristian <christian@zeitnitz.eu>
+# Author URI: https://github.com/zbchristian/
+# License: GNU General Public License v3.0
+# License URI: https://github.com/raspap/raspap-webgui/blob/master/LICENSE
+
+function _install_feature_firewall() {
+    name="feature firewall"
+
+    _install_log "Install $name"
+    _install_log " - copy configuration file"
+	# create config dir
+	sudo mkdir "/etc/raspap/networking/firewall" || _install_status 1 "Unable to create firewall config directory 
+    # copy firewall configuration 
+    sudo cp "$webroot_dir/config/iptables_rules.json" "/etc/raspap/networking/" || _install_status 1 "Unable to install client configuration ($name)"
+    _install_status 0
+}