download: Fix wrong arch in target images

Wrongly listing arm64 image as ARM 32-bit. Fix this.

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>

content/download.md

@@ -35,7 +35,7 @@ release images presented below for evaluation.
   | ----- | ------------------ |
   | [Intel 64-bit (amd64)]({{< image-url Stable amd64 target ostree >}}) | [bmap file]({{< image-url Stable amd64 target ostree bmap >}}) |
   | [ARM 32-bit (armhf)]({{< image-url Stable armhf target ostree >}}) | [bmap file]({{< image-url Stable armhf target ostree bmap >}}) |
-  | [ARM 32-bit (arm64)]({{< image-url Stable arm64 target ostree >}}) | [bmap file]({{< image-url Stable arm64 target ostree bmap >}}) |
+  | [ARM 64-bit (arm64)]({{< image-url Stable arm64 target ostree >}}) | [bmap file]({{< image-url Stable arm64 target ostree bmap >}}) |
 
   {{% notice note %}}
   No open graphical stack is available for the current stable release on the