core: update b64encode and b64decode doc (#84757)

lib/ansible/plugins/filter/b64decode.yml

@@ -15,6 +15,12 @@ DOCUMENTATION:
       description: A Base64 string to decode.
       type: string
       required: true
+    encoding:
+      description:
+        - The encoding to use to transform from a text string to a byte string.
+        - Defaults to using 'utf-8'.
+      type: string
+      required: false
 
 EXAMPLES: |
   # Base64 decode a string
@@ -23,6 +29,10 @@ EXAMPLES: |
   # Base64 decode the content of 'b64stuff' variable
   stuff: "{{ b64stuff | b64decode }}"
 
+  # Base64 decode the content with different encoding
+  stuff: "{{ 'QQBuAHMAaQBiAGwAZQAgAC0AIABPMIkwaDB/MAoA' | b64decode(encoding='utf-16-le') }}"
+  # => 'Ansible - くらとみ\n'
+
 RETURN:
   _value:
     description: The contents of the Base64 encoded string.

lib/ansible/plugins/filter/b64encode.yml

@@ -11,6 +11,12 @@ DOCUMENTATION:
       description: A string to encode.
       type: string
       required: true
+    encoding:
+      description:
+        - The encoding to use to transform from a text string to a byte string.
+        - Defaults to using 'utf-8'.
+      type: string
+      required: false
 
 EXAMPLES: |
   # Base64 encode a string
@@ -19,6 +25,10 @@ EXAMPLES: |
   # Base64 encode the content of 'stuff' variable
   b64stuff: "{{ stuff | b64encode }}"
 
+  # Base64 encode the content with different encoding
+  b64stuff: "{{ 'Ansible - くらとみ\n' | b64encode(encoding='utf-16-le') }}"
+  # => 'QQBuAHMAaQBiAGwAZQAgAC0AIABPMIkwaDB/MAoA'
+
 RETURN:
   _value:
     description: A Base64 encoded string.