update README

Author: fd6130

README.md

@@ -31,10 +31,27 @@ BILLPLZ_SANDBOX_SIGNATURE_KEY=
 ```yaml
 # /config/packages/fd_billplz.yaml
 fd_billplz:
-    fd_billplz:
-    api_key: "%env(BILLPLZ_API_KEY)%"
-    signature_key: "%env(BILLPLZ_SIGNATURE_KEY)%"
-    sandbox: "%env(bool:BILLPLZ_SANDBOX)%" # true or false
-    sandbox_api_key: "%env(BILLPLZ_SANDBOX_API_KEY)%"
-    sandbox_signature_key: "%env(BILLPLZ_SANDBOX_SIGNATURE_KEY)%"
+    enable_sandbox: "%env(bool:BILLPLZ_SANDBOX)%" # true or false
+    sandbox:
+        api_key: "%env(BILLPLZ_SANDBOX_API_KEY)%"
+        signature_key: "%env(BILLPLZ_SANDBOX_SIGNATURE_KEY)%"
+        collection: # add your bill collection here
+            - { name: "", id: ""} # "name" is the key name of the collection, "id" is the collection id
+    live:
+        api_key: "%env(BILLPLZ_API_KEY)%"
+        signature_key: "%env(BILLPLZ_SIGNATURE_KEY)%"
+        collection:
+            - { name: "", id: ""}
+```
+
+Usage
+-----
+
+```php
+function createPayment(BillplzInterface $billplz)
+{
+    $response = $billplz->createBill("collection_name", "[email protected]", null, "Lorem Ipsum", 100, "https://127.0.0.1/payment/success", "A new product", []);
+
+    // your own logic here...
+}
 ```