changed from relative to absolute links

Signed-off-by: David Karlsson <david.karlsson@docker.com>

docs/guides/cache/index.md

@@ -12,9 +12,9 @@ important to keep the runtime of image builds as low as possible.
 >
 > If you use secrets or credentials inside your build process, ensure you
 > manipulate them using the dedicated
-> [--secret](../../reference/buildx_build.md#secret) functionality instead of
-> using manually `COPY`d files or build `ARG`s. Using manually managed secrets
-> like this with exported cache could lead to an information leak.
+> [`--secret` option](https://docs.docker.com/engine/reference/commandline/buildx_build/#secret).
+> Manually managing secrets using `COPY` or `ARG` could result in leaked
+> credentials.
 
 ## Backends
 
@@ -44,14 +44,12 @@ Buildx supports the following cache storage backends:
 ## Command syntax
 
 To use any of the cache backends, you first need to specify it on build with the
-[`--cache-to`](../../reference/buildx_build.md#cache-to) option to export the
-cache to your storage backend of choice. Then, use the
-[`--cache-from`](../../reference/buildx_build.md#cache-from) option to import
-the cache from the storage backend into the current build. Unlike the local
-BuildKit cache (which is always enabled), all of the cache storage backends must
-be explicitly exported to, and explicitly imported from. All cache exporters
-except for the `inline` cache requires that you
-[select an alternative Buildx driver](../drivers/index.md).
+[`--cache-to` option](https://docs.docker.com/engine/reference/commandline/buildx_build/#cache-to) to export the cache to your storage backend of choice. Then,
+use the [`--cache-from` option](https://docs.docker.com/engine/reference/commandline/buildx_build/#cache-from) to import the cache from the storage backend into
+the current build. Unlike the local BuildKit cache (which is always enabled),
+all of the cache storage backends must be explicitly exported to, and explicitly
+imported from. All cache exporters except for the `inline` cache requires that
+you [select an alternative Buildx driver](../drivers/index.md).
 
 Example `buildx` command using the `registry` backend, using import and export
 cache: