Add a warning explaining the need for a default route for Kubernetes clusters

[atanasdinov]

No description provided.

[ranjinimn]

@atanasdinov Can you please provide more information for this issue?

[atanasdinov]

Yeah, sorry for not putting a description. We basically want to ensure that our docs also list the k3s and RKE2 route prerequisites:

• https://docs.rke2.io/install/airgap#prerequisites
• https://docs.k3s.io/installation/airgap#default-network-route

[ranjinimn]

@atanasdinov Thank you for this information. Can you please let me know the sections where you would like these prerequisites to be included? Do you want me to include these as links in the relevant sections?