fix: coupon -> voucher

Author: Chasen-Zhang

docs/fragment/03-pricing-cn.md

@@ -94,4 +94,4 @@
 
 要查看您的账单，请前往 **管理**，然后点击 **费用中心**。
 
-在进行扣费时，Databend Cloud 首先使用优惠券。如果有多个优惠券可用，系统会优先从到期日期最早的优惠券中扣除。请确保在优惠券到期前使用。
+在进行扣费时，Databend Cloud 首先使用代金券。如果有多个代金券可用，系统会优先从到期日期最早的代金券中扣除。请确保在代金券到期前使用。

docs/fragment/03-pricing-en.md

@@ -98,4 +98,4 @@ The billing period is set for every calendar month, starting from the 1st day to
 
 To check your billing details, go to **Manage** and then click on **Billing**. From there, you can review your bills and link a credit card for payment.
 
-When billing users, Databend Cloud applies coupons first. If multiple coupons are available, the system prioritizes deduction from the coupon with the earliest expiration date. Please ensure coupons are used before their expiration date.
+When billing users, Databend Cloud applies vouchers first. If multiple vouchers are available, the system prioritizes deduction from the voucher with the earliest expiration date. Please ensure vouchers are used before their expiration date.

i18n/en/code.json

@@ -449,9 +449,9 @@
     "message": "Databend Cloud Now Available",
     "description": "Databend Cloud Now Available"
   },
-  "Register now and get a $200 coupon": {
-    "message": "Register now and get a $200 coupon",
-    "description": "Register now and get a $200 coupon."
+  "Register now and get a $200 voucher": {
+    "message": "Register now and get a $200 voucher",
+    "description": "Register now and get a $200 voucher."
   },
   "What is Databend?": {
     "message": "What is Databend?",

i18n/zh/code.json

@@ -465,9 +465,9 @@
     "message": "Databend Cloud 现已开放注册",
     "description": "Databend Cloud Now Available"
   },
-  "Register now and get a $200 coupon": {
-    "message": "现在注册即可获得价值 200 元的优惠券",
-    "description": "Register now and get a $200 coupon."
+  "Register now and get a $200 voucher": {
+    "message": "现在注册即可获得价值 200 元的代金券",
+    "description": "Register now and get a $200 voucher."
   },
   "What is Databend?": {
     "message": "什么是 Databend?",