Feature 11002: Deprecate Helmv2

Signed-off-by: Luis Vega <lvega@whitestack.com>

05-osm-usage.md

@@ -1700,6 +1700,17 @@ osm repo-show bitnami
 ### KNF Service on-boarding and instantiation
 
 KNFs can be on-boarded using Helm Charts or Juju Bundles. In the following section is shown an example with Helm Chart and for Juju Bundles.
+Helm v2 has been deprecated since 2020. Starting from OSM REL15, we no longer support it. If you attempt to deploy a KNF using Helm v2, you will encounter the following error:
+
+```bash
+ERROR: Error 422: {
+    "code": "UNPROCESSABLE_ENTITY",
+    "status": 422,
+    "detail": "Error in pyangbind validation: {'error-string': 'helm_version must be of a type compatible with enumeration', 'defined-type': 'kdu:enumeration', 'generated-type': 'YANGDynClass(base=RestrictedClassType(base_type=six.text_type,                                     restriction_type=\"dict_key\",                                     restriction_arg={\\'v3\\': {}},), default=six.text_type(\"v3\"), is_leaf=True, yang_name=\"helm-version\", parent=self, choice=(\\'kdu-model\\', \\'helm-chart\\'), path_helper=self._path_helper, extmethods=self._extmethods, register_paths=True, namespace=\\'urn:etsi:osm:yang:augments:kdu\\', defining_module=\\'kdu\\', yang_type=\\'enumeration\\', is_config=True)'}"
+  }
+```
+
+To upgrade Helm from v2 to v3, follow the [official documentation](https://helm.sh/docs/topics/v2_v3_migration/)
 
 #### KNF Helm Chart