fix(medusa-plugin-sendgrid): Inject GiftCardService to eliminate undefined error (#2941)

docs/content/add-plugins/sendgrid.mdx

@@ -3608,8 +3608,9 @@ You don’t have to create a template for every type in the reference. You can s
   ```json noReport
   Object {
     "code": Any<String>,
-    "value": 4,
+    "value": 100,
     "balance": 100,
+    "display_value": "100.00",
     "region": Object {
       "automatic_taxes": true,
       "created_at": Any<Date>,
@@ -3937,7 +3938,7 @@ const plugins = [
       order_placed_template: process.env.SENDGRID_ORDER_PLACED_ID,
       localization: {
         "de-DE": { // locale key
-          order_placed_template: 
+          order_placed_template:
             process.env.SENDGRID_ORDER_PLACED_ID_LOCALIZED,
         },
       },