[VOL-5061] - docs.voltha.org: Update release page.On branch dev-joey

[VOL-5079]

conf.py
sphinx_conf/exclude_patterns.py
sphinx_conf/linkcheck_ignore.py
-------------------------------
  o Refactor large URL and path exclusion lists into separate files.
  o Update linkcheck release_notes/*.html patterns to exclude by regex.

release_notes/voltha_2.12.rst
-----------------------------
  o Update deployed package grid with current version strings.
  o Re-arrange structure to display 'artifacts', include links
    for pkg, pkg-app and pkg-api artifact downloads.
  o Replace sonatype/nexus urls(staging) with direct links to maven central.

requirements.txt
----------------
  o Added missing python package sphinx-reload.

howto/release/components/apache-karaf/
howto/release/components/atomix/
howto/release/components/onos/
--------------------------------------
  o Capture dependencies, version upgrades and sources to endit
    for current package release deployments.

To view changes live:
  o git checkout voltha-docs
  o cd voltha-docs
  o make reload

Change-Id: I7b88f9d4d3329abcbe98ebbb4dbb94587088f8b9
diff --git a/sphinx_conf/__init__.py b/sphinx_conf/__init__.py
new file mode 100644
index 0000000..299be16
--- /dev/null
+++ b/sphinx_conf/__init__.py
@@ -0,0 +1,20 @@
+# -*- python -*-
+'''Augment searchpath for import.'''
+
+##-------------------##
+##---]  IMPORTS  [---##
+##-------------------##
+import sys
+from pathlib import Path
+
+## ---------------------------------------
+## Artificial scope created for local vars
+## ---------------------------------------
+# pylint: disable=invalid-name
+# pylint: disable=using-constant-test
+if True:
+    mod_path = Path('..').resolve().as_posix()
+    if mod_path not in sys.path:
+        sys.path.insert(0, mod_path)
+
+# [EOF]