docs(calico): Add initial README

infrastructure/calico/README.md

+Calico
+---
+
+This component provides general networking to the cluster. The overlay network is kept simple since the goal are small scale clusters. However it uses Wireguard to encrypt all traffic within the cluster.
+
+**Hint:** *This component also has a bootstrap component.*
+
+Nice to knows
+---
+
+- The operator provides its own set of CRDs, examples from the docs, won't work by default. Operator uses `crd.projectcalico.org/v1` while calico itself uses `projectcalico.org/v3`
+
+Links
+---
+
+- [Docs](https://projectcalico.docs.tigera.io/about/about-calico)
+- [Helm Chart](https://artifacthub.io/packages/helm/projectcalico/tigera-operator)
+- [Source Code - Operator](https://github.com/tigera/operator)
+- [Source Code - Calico](https://github.com/projectcalico/calico)