[Cache] Update cache-reserve.mdx (cloudflare#25148)

Can we refer it to docs on Vary for Images?

Author: nenizera

src/content/docs/cache/advanced-configuration/cache-reserve.mdx

@@ -52,7 +52,7 @@ Not all assets are eligible for Cache Reserve. To be admitted into Cache Reserve
 
 - Cache Reserve file limits are the same as [R2 limits](/r2/platform/limits/). Note that [CDN cache limits](/cache/concepts/default-cache-behavior/#customization-options-and-limits) still apply. Assets larger than standard limits will not be stored in the standard CDN cache, so these assets will incur Cache Reserve operations costs far more frequently.
 - Origin Range requests are not supported at this time from Cache Reserve.
-- Vary for images is currently not compatible with Cache Reserve.
+- [Vary for images](/cache/advanced-configuration/vary-for-images/) is currently not compatible with Cache Reserve.
 - Requests to [R2 public buckets linked to a zone's domain](/r2/buckets/public-buckets/) will not use Cache Reserve. Enabling Cache Reserve for the connected zone will use Cache Reserve only for requests not destined for the R2 bucket.
 - Cache Reserve makes requests for uncompressed content directly from the origin. Unlike the standard Cloudflare CDN, Cache Reserve does not include the `Accept-Encoding: gzip` header when sending requests to the origin.
 - Cache Reserve is bypassed when using the Cloudflare [O2O](/cloudflare-for-platforms/cloudflare-for-saas/saas-customers/how-it-works/) setup.