add Vercel behavior info

Author: ethanpalm

advanced/subpath/route53-cloudfront.mdx

@@ -25,9 +25,10 @@ These paths should be configured to bypass CloudFront caching and pass through d
 
 ### Header forwarding requirements
 
-Ensure that CloudFront forwards the `HOST` header and client IP information correctly. This is critical for Vercel's verification processes.
+You must create a custom origin request policy that forwards the `HOST` header and client IP information correctly. This is critical for Vercel's verification processes.
 
-When using CloudFront with Vercel deployments, CloudFront automatically adds the `CloudFront-Viewer-Address` header containing the original client's IP address.
+1. Create a custom origin request policy named `VercelCloudFrontProxy`.
+2. Include the `Origin` and `CloudFront-Viewer-Address` headers.
 
 You must include the `CloudFront-Viewer-Address` header in your origin request policy or cache policy headers configuration to forward the header to your origin.
 
@@ -48,7 +49,7 @@ You must include the `CloudFront-Viewer-Address` header in your origin request p
 
 4. Select **Use: [SUBDOMAIN].mintlify.dev**.
 
-5. For "Cache key and origin requests", select **CachingOptimized**.
+5. For "Cache key and origin requests", select **CachingOptimized** for the "Cache policy".
 
   <Frame>
     ![Cloudfront "Create distribution" page showing "CachingOptimized" selected for the cache key and origin requests policy.](/images/cloudfront/caching-policy.png)
@@ -100,22 +101,24 @@ Select the **Create behavior** button and create the following behaviors.
 
 If you are deploying to Vercel, create a behavior for Vercel verification paths with a **Path pattern** of `/.well-known/*` and **Origin and origin groups** pointing to your main origin (the staging URL).
 
-For **Cache policy**, select `CachingDisabled` to ensure these verification requests pass through without caching.
+For "Cache policy", select **CachingDisabled** to ensure these verification requests pass through without caching.
 
 ### `/docs/*`
 
 Create a behavior with a **Path pattern** of `/docs/*` with **Origin and origin groups** pointing to the `.mintlify.dev` URL (in our case `acme.mintlify.dev`).
 
+For "Cache policy", select **CachingOptimized**. If you are using a Vercel deployment, select **VercelCloudFrontProxy** for the "Origin request policy."
+
 <Frame>
   ![Cloudfront "Create behavior" page with a "Path pattern" of "/docs/*" and "Origin and origin groups" pointing to the `acme.mintlify.dev` URL.](/images/cloudfront/behavior-1.png)
 </Frame>
 
-For **Cache policy**, select `CachingOptimized` and create behavior.
-
 ### `/docs`
 
 Create a behavior with a **Path pattern** of `/docs` and **Origin and origin groups** pointing to the same `.mintlify.dev` URL.
 
+If you are using a Vercel deployment, select **VercelCloudFrontProxy** for the "Origin request policy."
+
 <Frame>
   ![Cloudfront "Create behavior" page with a "Path pattern" of "/docs" and "Origin and origin groups" pointing to the `acme.mintlify.dev` URL.](/images/cloudfront/behavior-2.png)
 </Frame>