Update docs with addon provider

Author: alexander-demicev

docs/README.md

@@ -165,12 +165,13 @@ docker run -it --rm registry.k8s.io/capi-operator/cluster-api-operator:${CAPI_OP
 
 ## Basic Cluster API Provider Installation
 
-In this section, we will walk you through the basic process of installing Cluster API providers using the operator. The Cluster API operator manages four types of objects:
+In this section, we will walk you through the basic process of installing Cluster API providers using the operator. The Cluster API operator manages five types of objects:
 
 - CoreProvider
 - BootstrapProvider
 - ControlPlaneProvider
 - InfrastructureProvider
+- AddonProvider
 
 Please note that this example provides a basic configuration of Azure Infrastructure provider for getting started. More detailed examples and CRD descriptions will be provided in subsequent sections of this document.