Small improvement to docs

Author: fabriziopandini

docs/book/src/developer/providers/contracts/clusterctl.md

@@ -1,4 +1,4 @@
-# clusterctl Provider Contract
+# clusterctl Provider Contract (contract version v1beta2)
 
 The `clusterctl` command is designed to work with all the providers compliant with the following rules.
 

docs/book/src/developer/providers/contracts/control-plane.md

@@ -55,7 +55,7 @@ repo or add an item to the agenda in the [Cluster API community meeting](https:/
 
 </aside>
 
-## Rules (contract version v1beta1)
+## Rules (contract version v1beta2)
 
 | Rule                                                                 | Mandatory | Note                                                                                                                       |
 |----------------------------------------------------------------------|-----------|----------------------------------------------------------------------------------------------------------------------------|

docs/book/src/developer/providers/contracts/infra-cluster.md

@@ -41,7 +41,7 @@ repo or add an item to the agenda in the [Cluster API community meeting](https:/
 
 </aside>
 
-## Rules (contract version v1beta1)
+## Rules (contract version v1beta2)
 
 | Rule                                                                 | Mandatory | Note                                                                |
 |----------------------------------------------------------------------|-----------|---------------------------------------------------------------------|

docs/book/src/developer/providers/contracts/infra-machine.md

@@ -41,7 +41,7 @@ repo or add an item to the agenda in the [Cluster API community meeting](https:/
 
 </aside>
 
-## Rules (contract version v1beta1)
+## Rules (contract version v1beta2)
 
 | Rule                                                                 | Mandatory | Note                                 |
 |----------------------------------------------------------------------|-----------|--------------------------------------|

docs/book/src/developer/providers/contracts/overview.md

@@ -5,6 +5,8 @@ Those rules can be in the form of CustomResourceDefinition (CRD) fields and/or e
 
 Different rules apply to each provider type and for each different resource that is expected to interact with "core" Cluster API.
 
+See [Cluster API release vs contract versions](../../../reference/versions.md#cluster-api-release-vs-contract-versions) for info about current and supported contract versions.
+
 - Infrastructure provider
   - Contract rules for [InfraCluster](infra-cluster.md) resource
   - Contract rules for [InfraMachine](infra-machine.md) resource

docs/book/src/reference/providers.md

@@ -6,11 +6,14 @@ As part of this effort, everyone is welcome to add to the list below both provid
 by SIG Cluster Lifecycle as well as providers from other open-source repositories.
 
 Each provider is the responsibility of the respective maintainers and we highly recommend
-everyone interested in a specific provider to engage with the corresponding team or at least
-to read corresponding documentation carefully.
+everyone interested in a specific provider to engage with the corresponding team to show support, share use cases,
+learn more about the other users of the same provider. 
+
+We also recommend to read provider's documentation carefully, test it, and perform a proper
+due diligence before deciding to use a provider in production, like you will do for any other open source project.
 
 We are deeply thankful to all the the providers in the list, because they are a concrete proof
-of the liveness of the ecosystem,  a relevant part of the history of this community, and a valuable
+of the liveness of the ecosystem, a relevant part of the history of this community, and a valuable
 source of inspiration and ideas for others.
 
 ## Bootstrap