include Premium in plan listings and localize preview availability

Author: Oreoxmt

tidb-cloud/features.md

@@ -5,7 +5,7 @@ summary: Learn about feature support status for different TiDB Cloud plans.
 
 # Features
 
-This document lists the feature support status for different TiDB Cloud plans, including {{{ .starter }}}, Essential, and Dedicated.
+This document lists the feature support status for different TiDB Cloud plans, including {{{ .starter }}}, Essential, Premium, and Dedicated.
 
 > **Tip:**
 >

tidb-cloud/select-cluster-tier.md

@@ -13,6 +13,7 @@ TiDB Cloud provides the following options of plans. Whether you are just getting
 - [TiDB Cloud Starter](#starter)
 - [{{{ .essential }}}](#essential)
 - [TiDB Cloud Dedicated](#tidb-cloud-dedicated)
+- [ {{{ .premium }}}](#premium)
 
 > **Note:**
 >

tidb-cloud/tidb-cloud-intro.md

@@ -102,15 +102,21 @@ TiDB Cloud provides the following deployment options:
 
     </CustomContent>
 
-<CustomContent plan="premium">
-
 - {{{ .premium }}}
 
     {{{ .premium }}} is designed for mission-critical businesses that demand unlimited real-time scalability. It delivers workload-aware auto-scaling and comprehensive enterprise capabilities.
 
+    <CustomContent language="en,zh">
+
     Currently, {{{ .premium }}} is in public preview on AWS and Alibaba Cloud. 
 
-</CustomContent>
+    </CustomContent>
+
+    <CustomContent language="ja">
+
+    Currently, {{{ .premium }}} is in public preview on AWS.
+
+    </CustomContent>
 
 - TiDB Cloud Dedicated