doc: fix broken links

docs/en/04-get-started.md

@@ -4,4 +4,4 @@ title: Get Started
 description: A quick guide for how to access TDengine cloud service
 ---
 
-It's very convenient to access TDengine cloud service, just open your browser, connect to [TDengine Cloud Service Portal](cloud.tdengine.com), create an account with a valid email address, activate your account, then you will get a free TDengine cloud service. Enjoy!
+It's very convenient to access TDengine cloud service, just open your browser, connect to [TDengine Cloud Service Portal](https://cloud.tdengine.com), create an account with a valid email address, activate your account, then you will get a free TDengine cloud service. Enjoy!
\ No newline at end of file