update: remove outdated payment method examples and streamline README content

Author: vegimcarkaxhija

README.md

@@ -182,86 +182,6 @@ mutation doSepaPayment($cartId: String!, $returnUrl: String!) {
 }
 ```
 
-- Get the available payments methods with additional data for gateways:
-```graphql
-query {
-    cart(cart_id: "{ CART_ID }") {
-        available_payment_methods {
-            code
-            title
-            buckaroo_additional {
-                key
-                values {
-                    name
-                    code
-                    img
-                }
-                value
-            }
-        }
-    }
-}
-```
-
-- Place order request example: In order to place a order you will need to the following 3 steps:
-  - Set the payment method on the card with the required additional parameters using the default `setPaymentMethodOnCart` and the `buckaroo_additional` property
-  - Set the return url using our custom migration `setBuckarooReturnUrl` required in order for the payment engine to redirect back to your application after the payment was completed/canceled/failed
-  - Finally execute the the default `placeOrder` that will return a redirect url for the payment engine to complete the payment
-
-For iDEAL we have the following example:
-```graphql
-  mutation doBuckarooPayment(
-  $cartId: String!
-  $returnUrl: String!
-  $methodCode: String!
-) {
-  setPaymentMethodOnCart(
-    input: {
-      cart_id: $cartId
-      payment_method: {
-        code: $methodCode
-        buckaroo_additional: { buckaroo_magento2_ideal: { issuer: "ABNANL2A" } }
-      }
-    }
-  ) {
-    cart {
-      items {
-        product {
-          name
-          sku
-        }
-      }
-    }
-  }
-  setBuckarooReturnUrl(input: { return_url: $returnUrl, cart_id: $cartId }) {
-    success
-  }
-  placeOrder(input: { cart_id: $cartId }) {
-    order {
-      order_number
-      buckaroo_additional {
-        redirect
-        transaction_id
-        data {
-          key
-          value
-        }
-      }
-    }
-  }
-}
-
-```
-After this migration is performed you will need to store the buckaroo `transaction_id` and redirect the user to complete the payment
-
-In order to get the payment status after the user is redirected back we will use our custom migration `buckarooPaymentTransactionStatus` that will need the stored `transaction_id`
-
-```graphql
-mutation buckarooPaymentTransactionStatus(input: { transaction_id: "E397CF4C24E64AA299F45246F9906F45" }) {
-  payment_status,
-  status_code
-}
-```
 ### Additional information
 - **Support:** https://support.buckaroo.eu/contact
 - **Contact:** [support@buckaroo.nl](mailto:support@buckaroo.nl) or [+31 (0)30 711 50 50](tel:+310307115050)