[VOL-5329] - Update copyright docs to mention SPDX

overview/contributing/copyright.rst
overview/contributing/copyright/Makefile.rst
overview/contributing/copyright/copyright.rst
overview/contributing/copyright/golang.rst
overview/contributing/copyright/json.rst
overview/contributing/copyright/markdown.rst
---------------------------------------------
  o Add examples of copyright notice in source.
  o json syntax most difficult to add.
  o Document SPDX tokens.
  o Creat a containing folder copyright/ so documentation setup can be modular.

conf.py
release_notes/voltha_2.12.rst
-----------------------------
  o Sphinx replace:: feature stopped working, linkcheck reports broken urls.
  o Move mvn-* and jira string templates into conf.py as ext links.
  o Replace |token| with :token:.
  o Also shorten several verbatim URLs with :vol-{ger,git}: extlinks.

Change-Id: I0f9ec3f4354044968805da1872fc9f6bd864996f
Signed-off-by: Joey Armstrong <jarmstrong@linuxfoundation.org>
diff --git a/overview/contributing/copyright/markdown.rst b/overview/contributing/copyright/markdown.rst
new file mode 100644
index 0000000..e57068e
--- /dev/null
+++ b/overview/contributing/copyright/markdown.rst
@@ -0,0 +1,28 @@
+Copyright Notice: markdown syntax
+=================================
+
+.. code-block:: HTML
+   :caption: Markdown Syntax
+
+   <!--
+   # -----------------------------------------------------------------------
+   # Copyright 2017-2024 Open Networking Foundation Contributors
+   #
+   # Licensed under the Apache License, Version 2.0 (the "License");
+   # you may not use this file except in compliance with the License.
+   # You may obtain a copy of the License at
+   #
+   # http:#www.apache.org/licenses/LICENSE-2.0
+   #
+   # Unless required by applicable law or agreed to in writing, software
+   # distributed under the License is distributed on an "AS IS" BASIS,
+   # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   # See the License for the specific language governing permissions and
+   # limitations under the License.
+   # -----------------------------------------------------------------------
+   # SPDX-FileCopyrightText: 2017-2024 Open Networking Foundation Contributors
+   # SPDX-License-Identifier: Apache-2.0
+   # -----------------------------------------------------------------------
+   # Intent:
+   # -----------------------------------------------------------------------
+   -->