Add the usage guide for new CRD

docs/getting-started/update-configmap-using-crd.md

@@ -0,0 +1,19 @@
+## CompatibilityConfig
+
+The newly introduced CRD gives user a simpler way to update the compatibility matrix
+without using the `vdoctl`.
+
+To use the new CRD you can create the object referred below
+```shell
+apiVersion: vdo.vmware.com/v1alpha1
+kind: CompatibilityConfig
+metadata:
+  name: compat-matrix-config
+  namespace: vmware-system-vdo
+spec:
+  matrixURL: "https://github.com/vmware-tanzu/vsphere-kubernetes-drivers-operator/releases/download/0.3.0-rc/compatibility.yaml"
+```
+
+You can update the matrixURL as per your requirement.
+
+**Note** : Make sure you keep the name of the CompatibilityConfig(`compat-matrix-config`) unchanged. The namespace can be updated as per usage.