Misc doc edits for release.

release_notes/voltha_2.12.rst
-----------------------------
  o Update version and URLs for kafka
  o Update version and URLs for olt

howto/release/tasks/index.rst
howto/release/tasks/golang_gofmt_syntax.rst
-------------------------------------------
  o Document std golang formatting with gofmt -s -e -w.
  o Document content with references (commit message, make lint)
    diff --git a/howto/release/tasks/index.rst b/

Include a few edits from gerrit id I6e9658c23f436f83d423f74e01b2966943d2fe08

Change-Id: I27ad46ddd6673a9e35e794b1d3e8bb0644e8260d
diff --git a/howto/release/tasks/index.rst b/howto/release/tasks/index.rst
index 9507df2..3e305e4 100644
--- a/howto/release/tasks/index.rst
+++ b/howto/release/tasks/index.rst
@@ -14,14 +14,29 @@
 BUILD[pre-release]: dependency and module updates
 -------------------------------------------------
 
-- make go mod-update
-- Update copyright notices :ref:`Release Task Copyright`
+- :ref:`Release Task Golang Mod Update`
+- :ref:`Release Task Copyright`
 
 Standard syntax & formatting
 ----------------------------
 
 - Golang syntax fomatting :ref:`Release Task Golang Syntax`
 
+golang
+^^^^^^
+
+Use the gofmt command to reformat golang sources gathered outside the vendor/ directory.
+
+.. code-block:: shell-session
+   :caption: Standard syntax formatting for golang source
+
+   % make golang-fmt
+
+   % cd mysandbox
+   % find . ! -path './vendor/\*' -name '*.go' -print0 \
+     | xargs -n1 gofmt -s -e -w
+
+
 Chart.yaml
 ----------