Misc updates related to release.

howto/release/components/index.rst
howto/release/components/maclearner/index.rst
howto/release/components/olttopology/index.rst
howto/release/components/pppoeagent/index.rst
----------------------------------------------
  o Document maven plugins and dependencies for components.

config.mk
---------
  o Disable yaml linting for now, volume problems to cleanup.

howto/code/index.rst
howto/code/job-failures.rst
---------------------------
  o Added a new page for documenting common jenkins problems.

howto/release/checklist.rst
howto/release/preparation.rst
overview/contributing.rst
release_notes/release_process.rst
---------------------------------
  o Incremental edits related to release steps.

Change-Id: I84db4d422556dbbeeaa5bf5351060dc193585e40
diff --git a/howto/code/index.rst b/howto/code/index.rst
index 0d23582..685dc2a 100644
--- a/howto/code/index.rst
+++ b/howto/code/index.rst
@@ -4,5 +4,6 @@
 .. toctree::
    :maxdepth: 2
 
+   job-failures
    linting
    pull_request