add clean up info

Author: cyyeh

packages/doc/docs/deployment/flydotio.mdx

@@ -181,4 +181,8 @@ Visit your newly deployed app at https://xxxxx/
 You can read more here regarding to [deployment via Dockerfile](https://fly.io/docs/languages-and-frameworks/dockerfile/).
 :::
 
-Congratulations! Now your VulcanSQL app is on the cloud and is ready to be shared to the world!
+Congratulations! Now your VulcanSQL app is on the cloud and is ready to be shared to the world!
+
+:::info
+If you need to clean up the resources on Fly.io, you can [read the documentation here](https://fly.io/docs/flyctl/destroy/).
+:::

packages/doc/docs/deployment/gcp-app-engine.mdx

@@ -95,4 +95,8 @@ To view your application in the web browser run:
   $ gcloud app browse
 ```
 
-Congratulations! Now your VulcanSQL app is on the cloud and is ready to be shared to the world!
+Congratulations! Now your VulcanSQL app is on the cloud and is ready to be shared to the world!
+
+:::info
+If you need to clean up the resources on App Engine, you can [read the documentation here](https://cloud.google.com/appengine/docs/standard/python3/building-app/cleaning-up).
+:::

packages/doc/docs/deployment/gcp-cloud-run.mdx

@@ -100,4 +100,8 @@ Service [vulcansql-project] revision [vulcansql-project-00001-mud] has been depl
 Service URL: https://vulcansql-project-ggcxvljfba-df.a.run.app
 ```
 
-Congratulations! Now your VulcanSQL app is on the cloud and is ready to be shared to the world!
+Congratulations! Now your VulcanSQL app is on the cloud and is ready to be shared to the world!
+
+:::info
+If you need to clean up the resources on Cloud Run, you can [read the documentation here](https://cloud.google.com/run/docs/quickstarts/build-and-deploy/deploy-nodejs-service#clean-up).
+:::