Improve readme usage example

Author: morgante

README.md

@@ -34,31 +34,31 @@ You can go to the examples folder, however the usage of the module could be like
 
 ```hcl
 module "vpc" {
-    source     = "../../"
+    source = "github.com/terraform-google-modules/terraform-google-network"
     project_id = "<PROJECT ID>"
     vpc_name   = "example-vpc"
 
     subnets = [
         {
-        subnet_name           = "subnet-01"
-        subnet_ip             = "10.10.10.0/24"
-        subnet_region         = "us-west1"
-        subnet_private_access = false
+            subnet_name           = "subnet-01"
+            subnet_ip             = "10.10.10.0/24"
+            subnet_region         = "us-west1"
+            subnet_private_access = false
         },
         {
-        subnet_name           = "subnet-02"
-        subnet_ip             = "10.10.20.0/24"
-        subnet_region         = "us-west1"
-        subnet_private_access = false
+            subnet_name           = "subnet-02"
+            subnet_ip             = "10.10.20.0/24"
+            subnet_region         = "us-west1"
+            subnet_private_access = false
         },
     ]
 
     secondary_ranges = {
         subnet-01 = [
-        {
-            range_name    = "subnet-01-secondary-01"
-            ip_cidr_range = "192.168.64.0/24"
-        },
+            {
+                range_name    = "subnet-01-secondary-01"
+                ip_cidr_range = "192.168.64.0/24"
+            },
         ]
 
         subnet-02 = []