VOL-4840 - Makefile edits

VOL-4874, VOL-4877, VOL-4840

howto/edit_voltha_docs.rst
--------------------------
   * Also need to run "make docs" to generate html content.

Makefile
--------
   * (local use) fixed non-functional makefile targets.
   * Begin splitting monolithic makefile into reusable libs.
   * Extended help to document all targets (make help VERBOSE=1)
   * Extended lint to support more targets.
   * Replace wildcard target (%) with a list of sphinx-build named targets:
     + Amusing behavior but "make clean" should not initiate "gendocs".
     + Likewise "make lint" should not attempt to generate documentation.
   * Introduced simple patching logic for virtualenv.  Local users are
     now able to use make clean, lint, etc with a newer interpreter.
     Baby steps toward VOL-4874.
   * Conditional make vars added:
     + NO_PATCH=1
     + NO_OTHER_REPO_DOCS=1 (venv patching not yet supported by foreign repos).

makefiles/consts.mk
-------------------
   * basic values: space, dot, null, HIDE.

makefiles/help/include.mk
-------------------------
   * makefile target help with context.

makefiles/lint/*.mk
-------------------
   * lib makefiles capturing syntax checking logic.

makefiles/patches/include.mk
----------------------------
   * Targets for creation and applying python virtualenv patches.

patches/*/patch
patches/python_310_migration.sh
-------------------------------
   * Logic used to support dynamic python module pathching in a virtual env directory.
   * Module edits are trivial -- attempt to import new modules and fallback to existing import syntax.

Change-Id: I437289a751423217b4193b75b62c4a295db18ffd
diff --git a/howto/code/pull_request.rst b/howto/code/pull_request.rst
new file mode 100644
index 0000000..677e4e2
--- /dev/null
+++ b/howto/code/pull_request.rst
@@ -0,0 +1,23 @@
+VOLTHA project repositories
+===========================
+
+Development and code reviews:
+-----------------------------
+
+Commit decorations:
++++++++++++++++++++
+
+`Tokens
+<https://docs.voltha.org/master/testing/voltha_test_automation.html#per-patchset-verification-jobs>`_ can be embedded within a commit message to enable running additional test suites as part of jenkins validation.
+
+NOTE:
++++++
+There have been a few reports of testing not being triggered by a commit.
+If you encounter this behavior visit the VOLTHA jira site and open a ticket.
+Commit hooks can be repository specific and may need to be deployed/enabled to support functionality.
+
+- :vol-jira:``
+- Include gerrit URL for your changeset.
+- Target repository name/url.
+- What tests or suites were expected that were not exercised.
+