[Docs] Document Support matrix

[cruizen]

• Support matrix – list out tested K8s version, ArgoCD and ClusterAPI
  cc: @cre8minus1

e.g. We support ArgoCD 2.2 and CAPI 1.0 in Arlon v0.3, ArgoCD 2.4 and CAPI 1.1 in Arlon v0.9
We have tested with k8s version up to v1.24 in Arlon 0.9

Aha! Link: https://pf9.aha.io/features/ARLON-409

[Rohitrajak1807]

E2E tests may be able to help.

[cruizen]

Hey team! Please add your planning poker estimate with Zenhub @bcle @cruizen @jayanth-tjvrr @Rohitrajak1807 @ShaunakJoshi1407