Update releasenotes and documentation

docs/paymentmethods.md

+# Payment Methods
+
+The Stripe extension implements the following payment methods:
+
+## Credit / Debit Card
+
+### Card Element
+
+See: [Stripe Card Element](https://stripe.com/docs/payments/payment-methods/overview#cards).
+
+![card element](images/element_card.png)
+
+This is enabled by default. No additional configuration is required.
+
+It is supported for all payment types.
+
+### Payment Request Button (Apple/Google/Microsoft Pay)
+
+See: [Stripe PaymentRequest Button](https://stripe.com/docs/stripe-js/elements/payment-request-button).
+
+![paymentrequest element](images/element_paymentrequest.png)
+
+#### Configuration
+
+In *Administer->CiviContribute->Stripe Settings* you need to set `Country where your account is registered` to
+ the two character country code of your account (eg. "US").
+
+#### Supported configurations
+
+The PaymentRequest element will be displayed automatically instead of the card element if:
+1. The client browser has support for the paymentRequest button.
+2. The payment is a *one-off*. Recurring payments are not supported and the element will not be displayed in this case.

docs/releasenotes.md

@@ -18,6 +18,8 @@ Releases use the following numbering system:
 * Handle 3d-secure authentication on thankyou page for "setupIntents". This will happen when a delayed recurring contribution is created and the card issuer requests additional authentication.
 * Remove AJAX endpoint `civicrm/stripe/confirm-payment` and replace with `StripePaymentintent.Process` API call.
 * Add `StripePaymentintent.createorupdate` API which is used by the frontend javascript and requires "make online contributions" permission.
+* Simplify Stripe.Ipn API.
+* Fully remove support for CiviCRM older than 5.28.
 
 ## Release 6.5.8