Documentation update for kubernetes.core.helm (#317)

Documentation update for kubernetes.core.helm

Clarify usage of the module for doing helm repo update only.
I used collection_prep_add_docs as explained in CONTRIBUTING.md, not sure if
that's correct ?
Fixes #316
@Akasurde

Reviewed-by: Abhijeet Kasurde <None>
Reviewed-by: Mike Graves <mgraves@redhat.com>
Reviewed-by: None <None>

plugins/modules/helm.py

@@ -87,7 +87,7 @@ options:
     version_added: '1.1.0'
   update_repo_cache:
     description:
-      - Run C(helm repo update) before the operation. Can be run as part of the package installation or as a separate step.
+      - Run C(helm repo update) before the operation. Can be run as part of the package installation or as a separate step (see Examples).
     default: false
     type: bool
 
@@ -205,6 +205,13 @@ EXAMPLES = r"""
     state: absent
     wait: true
 
+- name: Separately update the repository cache
+  kubernetes.core.helm:
+    name: dummy
+    namespace: kube-system
+    state: absent
+    update_repo_cache: true
+
 # From git
 - name: Git clone stable repo on HEAD
   ansible.builtin.git: