chore: updated rules in readme example to resolve issue #252 (#253)

Author: tdigangi

modules/firewall-rules/README.md

@@ -13,23 +13,19 @@ module "firewall_rules" {
   network_name = module.vpc.network_name
 
   rules = [{
-    name = "allow-ssh-ingress"
-    priority = null
-    description = null
-    direction = "INGRESS"
-    ranges = ["0.0.0.0/0"]
-    source = {
-      tags = null
-      service_accounts = null
-    }
-    target = {
-      tags = null
-      service_accounts = null
-    }
+    name                    = "allow-ssh-ingress"
+    description             = null
+    direction               = "INGRESS"
+    priority                = null
+    ranges                  = ["0.0.0.0/0"]
+    source_tags             = null
+    source_service_accounts = null
+    target_tags             = null
+    target_service_accounts = null
     allow = [{
       protocol = "tcp"
-      ports = ["22"]
-     }]
+      ports    = ["22"]
+    }]
     deny = []
     log_config = {
       metadata = "INCLUDE_ALL_METADATA"