Update update-auth-page-content.mdx

Added definitions to obfuscated email

Author: clairekinde11

src/content/docs/design/content-customization/update-auth-page-content.mdx

@@ -40,9 +40,9 @@ Variables can be used on pages as follows.
 
 **Sign in confirm code page**
 
-`${email_address}`
+`${email_address}` - shows the full email address of the user
 
-`${email_address_obfuscated}`
+`${email_address_obfuscated}` - shows only a part of the user's email
 
 **Sign up confirm code page**