helmfile: add page (#22490)

Co-authored-by: Sahil Afrid Farookhi <msafarookhi@gmail.com>

pages/common/helmfile.md

@@ -0,0 +1,36 @@
+# helmfile
+
+> Declare and manage Helm releases and related Kubernetes manifests.
+> More information: <https://helmfile.readthedocs.io>.
+
+- Install required Helm plugins:
+
+`helmfile init`
+
+- Preview the changes that would be applied to the cluster:
+
+`helmfile diff`
+
+- Apply releases defined in `helmfile.yaml` to the cluster:
+
+`helmfile apply`
+
+- Synchronize the cluster with the desired state, force-recreating if needed:
+
+`helmfile sync`
+
+- Apply releases for a specific environment:
+
+`helmfile {{[-e|--environment]}} {{dev|production|staging}} apply`
+
+- Destroy all releases defined in `helmfile.yaml`:
+
+`helmfile destroy`
+
+- Display help:
+
+`helmfile {{[-h|--help]}}`
+
+- Display version:
+
+`helmfile version`