docs: describes usage of plugin

packages/medusa-plugin-sendgrid/src/services/sendgrid.js

@@ -121,6 +121,8 @@ class SendGridService extends NotificationService {
         return this.userPasswordResetData(eventData, attachmentGenerator)
       case "customer.password_reset":
         return this.customerPasswordResetData(eventData, attachmentGenerator)
+      case "restock-notification.restocked":
+        return await this.restockNotificationData(eventData, attachmentGenerator)
       default:
         return {}
     }
@@ -154,6 +156,8 @@ class SendGridService extends NotificationService {
         return this.options_.user_password_reset_template
       case "customer.password_reset":
         return this.options_.customer_password_reset_template
+      case "restock-notification.restocked":
+        return this.options_.medusa_restock_template
       default:
         return null
     }
@@ -671,6 +675,19 @@ class SendGridService extends NotificationService {
     }
   }
 
+  async restockNotificationData({ variant_id, emails }) {
+    const variant = await this.productVariantService_.retrieve(variant_id, {
+      relations: ["product"]
+    })
+
+    return {
+      product: variant.product,
+      variant,
+      variant_id,
+      emails
+    }
+  }
+
   userPasswordResetData(data) {
     return data
   }
@@ -698,7 +715,9 @@ class SendGridService extends NotificationService {
     }
 
     const normalized = humanizeAmount(amount, currency)
-    return normalized.toFixed(zeroDecimalCurrencies.includes(currency.toLowerCase()) ? 0 : 2)
+    return normalized.toFixed(
+      zeroDecimalCurrencies.includes(currency.toLowerCase()) ? 0 : 2
+    )
   }
 
   normalizeThumbUrl_(url) {