Fix heading levels

Author: shahednasser

www/apps/cloud/app/environments/preview/page.mdx

@@ -108,15 +108,15 @@ You can change the environment from which the preview environment's database is
 
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-### Preview Environment Inactivity
+## Preview Environment Inactivity
 
 Since Preview environments are only meant for testing, they are put to sleep after ten minutes of inactivity.
 
 So, if you're testing scheduled jobs or events, they may not work as expected in preview environments. They will work as expected in long-lived environments, such as Staging or Production.
 
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-### Delete Preview Environment
+## Delete Preview Environment
 
 Preview environments are automatically deleted when their PR is merged or closed. However, you can also delete them manually if needed.