[VOL-5252] Update release matrix for repo:voltha-openonu-adapter-go

release_notes/voltha_2.12.rst
-----------------------------
  o Update release matrix with onu-adapter-go artifact and chart version.

howto/release/tasks/charts.rst
------------------------------
  o Create an anchored document for chart editing.
  o This common document can then be referenced by per-repo chart edit docs.

howto/release/charts/notes.rst
howto/release/charts/voltha-openolt-adapter.rst
howto/release/charts/voltha-openonu-adapter.rst
-----------------------------------------------
  o Document edits for openonu.
  o Re-arrange some of the content.

howto/code/index.rst
howto/code/lint/
howto/code/linting.rst
----------------------
  o Move help topics lint-chart and lint-helm into an individual rst file.
  o This helps support creation of an anchor for document linking.

Change-Id: I03bf4742a3ce8075c93827004466f9c1d7408859
diff --git a/howto/code/index.rst b/howto/code/index.rst
index 4639434..c9d6af7 100644
--- a/howto/code/index.rst
+++ b/howto/code/index.rst
@@ -7,6 +7,7 @@
    commit-message
    job-failures
    linting
+   lint/index
    pull_request
    release-bugfix
    voltha-protos