edit pm changes

Author: duongau

articles/frontdoor/standard-premium/how-to-configure-https-custom-domain.md

@@ -131,7 +131,7 @@ In order for the certificate to be automatically rotated to the latest version w
 
 If you want to change the secret version from ‘Latest’ to a specified version or vice versa, add a new certificate. 
 
-### How to switch between certificate types
+## How to switch between certificate types
 
 1. You can change an existing Azure managed certificate to a user-managed certificate by selecting the certificate state to open the **Certificate details** page.
 
@@ -142,8 +142,8 @@ If you want to change the secret version from ‘Latest’ to a specified versio
 
     > [!NOTE]
     > * It may take up to an hour for the new certificate to be deployed when you switch between certificate types.
-    > If your domain state is Approved, switching certificate type between BYOC and managed certificate causes zero downtime. While switching to managed certificate, unless the domain ownership is revalidated and the domain state becomes Approved, you will continue to be served by the previous certificate.
-    > If you switch from BYOC to managed certificate, domain revalidation is required. if you switch from managed certificate to BYOC, there is no need for a domain re-validation.
+    > * If your domain state is Approved, switching the certificate type between BYOC and managed certificate won't have any downtime. Whhen switching to managed certificate, unless the domain ownership is re-validated and the domain state becomes Approved, you will continue to be served by the previous certificate.
+    > * If you switch from BYOC to managed certificate, domain re-validation is required. If you switch from managed certificate to BYOC, you're not required to re-validate the domain.
     >
 
     :::image type="content" source="../media/how-to-configure-https-custom-domain/certificate-details-page.png" alt-text="Screenshot of certificate details page.":::