update the stripe ops docs with new values

docs/ops/stripe.rst

 We use Stripe for payment processing.
 We have test-mode keys for use in staging and live-mode keys for use in production.
 
-There is "product" state in Stripe to facilitate the payment workflow.
-This was created with ``admin/create-product.sh``
+There is "payment link" state in Stripe to facilitate the payment workflow.
+This was created with ``admin/create-payment-link.sh``
 (once for test-mode and once for live-mode).
 
-The test-mode product is:
-
-```js
-{
-  "id": "prod_MhKpVSNW6zAsOG",
-  "object": "product",
-  "active": true,
-  "attributes": [],
-  "created": 1666977337,
-  "default_price": "price_1Lxw9dBHXBAMm9bPgDW93Bwz",
-  "description": "30 GiB-months of Private.Storage storage × time",
-  "images": [],
-  "livemode": false,
-  "metadata": {},
-  "name": "30 GiB-months",
-  "package_dimensions": null,
-  "shippable": null,
-  "statement_descriptor": "PRIVATE STORAGE",
-  "tax_code": null,
-  "type": "service",
-  "unit_label": null,
-  "updated": 1666977337,
-  "url": "https://private.storage/"
-}
-```
-
-The live-mode product is:
-
-```js
-XXX
-```
+The payment links can be found in PrivateStorageOps.
+They are the values of the stage3 variables ``stripe_payment_link_staging`` and ``stripe_payment_link_production``.
 
 There is also "webhook" state in Stripe so that PaymentServer receives notification of payment.
 This was created with ``admin/create-webhook.sh``
 (once for test-mode and once for live-mode).
-
-The test-mode webhook is:
-
-```js
-{
-  "id": "we_1LxwKnBHXBAMm9bPDJXJNcDN",
-  "object": "webhook_endpoint",
-  "api_version": null,
-  "application": null,
-  "created": 1666978029,
-  "description": null,
-  "enabled_events": [
-    "checkout.session.completed"
-  ],
-  "livemode": false,
-  "metadata": {},
-  "secret": "<REDACTED>"",
-  "status": "enabled",
-  "url": "https://payments.privatestorage-staging.com/v1/stripe/webhook"
-}
-```
-
-The live-mode webhook is:
-
-```js
-XXX
-```
-
-The webhook secrets are redacted here.
-They can be found with the rest of the each grid's private keys.
+The test-mode webhook is ``we_1LxwKnBHXBAMm9bPDJXJNcDN``.
+The live-mode webhook is ``we_1LzioNA9OAm23rYOmAcp3V85``.
+The webhook secrets can be found with the rest of the each grid's private keys in ``stripe.webhook-secret``.