Allow extraManifests to be specified (#1495)

* Update talconfig.yaml.j2

Allow extraManifests to be specified.

* Update config.sample.yaml

Allow extraManifests to be specified.

bootstrap/templates/kubernetes/bootstrap/talos/talconfig.yaml.j2

@@ -86,6 +86,12 @@ nodes:
     patches:
       - "@./patches/node_#{ item.name }#.yaml"
     #% endif %#
+    #% if item.manifests %#
+    extraManifests:
+      #% for manifest in item.manifests %#
+      - #{ manifest }#
+      #% endfor %#
+    #% endif %#
   #% endfor %#
 
 patches: