Add Explicit Section for Prerequisites

Egde version of Radius CLI installation requires Oras as a prerequisite. Currently it is bundled with rest of the content and is easy to miss until you hit an error while trying to install Radius CLI.

Signed-off-by: Karishma Chawla <[email protected]>

docs/content/installation/index.md

@@ -10,6 +10,9 @@ Radius consists of a set of tools and services that together form the Radius pla
 
 {{< image src="radius.png" alt="Diagram showing rad CLI and VSCode extension on local machine plus the Radius control plane on a Kubernetes cluster" width="600px" >}}
 
+## Prerequisites
+For edge version, Oras installation is required: https://oras.land/docs/installation.
+
 ## Step 1: Install the rad CLI
 
 {{< read file= "/shared-content/installation/rad-cli/install-rad-cli.md" >}}
@@ -22,4 +25,4 @@ Radius consists of a set of tools and services that together form the Radius pla
 
 {{< read file= "/shared-content/installation/install-radius/initialize-radius.md" >}}
 
->If you are looking to upgrade Radius to the latest version, refer to [upgrade Radius on Kubernetes]({{< ref kubernetes-upgrade >}}) for more information.
+>If you are looking to upgrade Radius to the latest version, refer to [upgrade Radius on Kubernetes]({{< ref kubernetes-upgrade >}}) for more information.