Add docs

plugins/filter/k8s.py

@@ -1,12 +1,50 @@
 # Copyright (c) 2017 Ansible Project
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
-
+# SPDX-License-Identifier: GPL-3.0-or-later
 
 from __future__ import absolute_import, division, print_function
 
 __metaclass__ = type
 
 
+DOCUMENTATION = r"""
+
+name: k8s_config_resource_name
+short_description: Generate resource name for the given resource of type ConfigMap, Secret
+description:
+  - Generate resource name for the given resource of type ConfigMap, Secret.
+  - Resource must have a C(metadata.name) key to generate a resource name
+options:
+  _input:
+    description:
+      - A valid YAML definition for a ConfigMap or a Secret.
+    type: dict
+    required: true
+author:
+  - ansible cloud team
+
+"""
+
+EXAMPLES = r"""
+  # Dump generated name for a configmap into a variable
+  - set_fact:
+      generated_name: '{{ definition | kubernetes.core.k8s_config_resource_name }}'
+    vars:
+      definition:
+        apiVersion: v1
+        kind: ConfigMap
+        metadata:
+          name: myconfigmap
+          namespace: mynamespace
+"""
+
+RETURN = r"""
+  _value:
+    description: Generated resource name.
+    type: str
+"""
+
+
 from ansible.errors import AnsibleFilterError
 from ansible_collections.kubernetes.core.plugins.module_utils.hashes import (
     generate_hash,