add crio registry mirror support (#6977)

* add crio registry mirror support

* mdlint fix

docs/cri-o.md

@@ -8,7 +8,7 @@ Kubespray supports basic functionality for using CRI-O as the default container
 
 _To use the CRI-O container runtime set the following variables:_
 
-## all.yml
+## all/all.yml
 
 ```yaml
 download_container: false
@@ -16,7 +16,7 @@ skip_downloads: false
 etcd_kubeadm_enabled: true
 ```
 
-## k8s-cluster.yml
+## k8s-cluster/k8s-cluster.yml
 
 ```yaml
 container_manager: crio
@@ -28,4 +28,21 @@ container_manager: crio
 etcd_deployment_type: host # optionally and mutually exclusive with etcd_kubeadm_enabled
 ```
 
+## all/crio.yml
+
+Enable docker hub registry mirrors
+
+```yaml
+crio_registries_mirrors:
+  - prefix: docker.io
+    insecure: false
+    blocked: false
+    location: registry-1.docker.io
+    mirrors:
+      - location: 192.168.100.100:5000
+        insecure: true
+      - location: mirror.gcr.io
+        insecure: false
+```
+
 [CRI-O]: https://cri-o.io/