message: [Doc] Update README with  field purpose and how to set default value
diff: @@ -18,15 +18,20 @@ type Descriptor = {
  displayName: string;
  description: string;
  'x-descriptors': SpecCapability[] | StatusCapability[]; // Used to determine which "capabilities" this descriptor has, and which React component to use
  - value?: any; // Optional value
  + value?: any; /* Optional field (type: object).
  + If present, the value of this spec is the same for all instances of the CRD
  + and can be found here instead of on the CR. */
  }
  ```
  The `x-descriptors` field can be thought of as "capabilities" (and is referenced in the code using this term). Capabilities are defined in `types.ts` provide a mapping between descriptors and different UI components (implemented as React components) using [URN format](https://en.wikipedia.org/wiki/Uniform_Resource_Identifier).
  +The `value` field is an optional field. If present, the value of this spec is the same for all instances of the CRD and can be found here instead of on the CR. You can specify the default value of the field on CRD in [OpenAPI v3 validation schema](https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/#defaulting).
  +
  +
  ## Example
  -From the `ClusterServiceVersion` for [etcd-operator](https://github.com/operator-framework/operator-lifecycle-manager/blob/master/deploy/chart/catalog_resources/ocs/etcdoperator.v0.9.2.clusterserviceversion.yaml):
  +From the `ClusterServiceVersion` for [etcd-operator](https://github.com/operator-framework/community-operators/blob/master/community-operators/etcd/0.9.4/etcdoperator.v0.9.4.clusterserviceversion.yaml#L30-L81):
  ```yaml
  - name: etcdclusters.etcd.database.coreos.com
  