[VOL-5194] - Refactor and use repo:onf-make as a git-submodule

makefiles/lint/doc8/doc8.ini
makefiles/lint/doc8/ini.mk
----------------------------
  o Repo:onf-make library makefiles define a default config for doc8.
  o Per-repository overrides and exclusions are needed for linting.
  o The doc8 command will err when multiple --config switches are passed.
  o ini.mk was added to dynamically generate a doc8.ini config
    file by merging library and local doc8 configs.

config.mk
---------
  o Added a deprecation note for config values moving to repo:voltha-docs.
  o Explicitly define --repo-name--, we lose per-repository error checking
    but the edit is needed to enable jenkins lint testing for repo:onf-make.

makefiles/include.mk
makefiles/.gitignore
--------------------
  o Define onf-mk-tmp=makefiles/tmp for internal library makefile use.
  o Targets and 'make clean' maintain the temp directory.

makefiles/lint/doc8/include.mk
------------------------------
  o include ini.mk to generate a doc8.ini config file.
  o Update lint target to support common *-{all, mod, src} targets.
  o help targets: replace echo with printf for consistent formatting.
  o Added banner-{enter,leave} calls and fixed a typo.

makefiles/lint/doc8/install.mk
------------------------------
  o Rename peripheral doc8 help target to lint-doc8-help.
    Output from 'make help' is growing long and difficult to read.
    Simplify by displaying two help items per topic (primary and summary),
    devs can later request topic specific help by name when needed.

Change-Id: I7c83bd48d26510e79fd32f8bb97887cace67b55f
diff --git a/.gitignore b/.gitignore
index b4cb667..bb2d999 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,8 @@
 .venv/
 __pycache__/
 
+tmp/
+
 ## Python patch creation
 staging/