enabler: Add initial docs for using network device images

internal-lab-setup-assets/images/README.md

@@ -1,5 +1,19 @@
+# Network Device Images
+
 This folder is intended to contain images used by emulated network devices in ContainerLab.
 
 The images are not included in the git repository for obvious reasons.
 - Licensing
-- Size
+- Size
+
+But... if you happen to have the Cisco XRd image from CCO, here are some notes.
+
+## Cisco XRd Control Plane
+
+1. Retrieve control plane version of XRd from Cisco: https://software.cisco.com/download/home/286331236/type/280805694
+
+2. Move it into the `images/` folder in this repository on your lab VM.
+
+3. Load it into docker and tag it locally
+  - `docker load -i xrd-control-plane-container-x64.dockerv1.tgz`
+  - `docker tag localhost/ios-xr:7.11.1 localhost/xrd-control-plane` (note: match the version to the one you downloaded, which may be newer)