docs: Add default extension config name in docs (#143)

Author: jimmidyson

docs/content/audit-policy.md

@@ -18,7 +18,7 @@ spec:
   patches:
     - name: audit-policy
       external:
-        generateExtension: "auditpolicypatch.<external-config-name>"
+        generateExtension: "auditpolicypatch.capi-runtime-extensions"
 ```
 
 Applying this configuration will result in new bootstrap files on the `KubeadmControlPlaneTemplate`.

docs/content/cluster-config.md

@@ -19,8 +19,8 @@ spec:
   patches:
     - name: cluster-config
       external:
-        generateExtension: "clusterconfigpatch.<external-config-name>"
-        discoverVariablesExtension: "clusterconfigvars.<external-config-name>"
+        generateExtension: "clusterconfigpatch.capi-runtime-extensions"
+        discoverVariablesExtension: "clusterconfigvars.capi-runtime-extensions"
 ```
 
 On the cluster resource then specify desired certificate SANs values:

docs/content/extra-apiserver-cert-sans.md

@@ -17,8 +17,8 @@ spec:
   patches:
     - name: apiserver-cert-sans
       external:
-        generateExtension: "extraapiservercertsanspatch.<external-config-name>"
-        discoverVariablesExtension: "extraapiservercertsansvars.<external-config-name>"
+        generateExtension: "extraapiservercertsanspatch.capi-runtime-extensions"
+        discoverVariablesExtension: "extraapiservercertsansvars.capi-runtime-extensions"
 ```
 
 On the cluster resource then specify desired certificate SANs values:

docs/content/http-proxy.md

@@ -17,8 +17,8 @@ spec:
   patches:
     - name: http-proxy
       external:
-        generateExtension: "httpproxypatch.<external-config-name>"
-        discoverVariablesExtension: "httpproxyvars.<external-config-name>"
+        generateExtension: "httpproxypatch.capi-runtime-extensions"
+        discoverVariablesExtension: "httpproxyvars.capi-runtime-extensions"
 ```
 
 On the cluster resource then specify desired HTTP proxy values: