VOL-5336 - Install pre-commit linting tool

.pre-commit-config.yaml
requirements.txt
-----------------------
  o Install pre-commit tool dependencies.

makefiles/include.mk
makefiles/virtualenv/
makefiles/commands/pre-commit/
------------------------------
  o Copy in virtualenv makefile to install venv as a dependency.
  o Copy in commands/pre-commit to support '% make pre-commit'

[HOWTO: test]
% make pre-commit

Change-Id: I59cf029374db6924a67771ca4511a904b4788269
diff --git a/makefiles/include.mk b/makefiles/include.mk
index bdb2203..edd002f 100644
--- a/makefiles/include.mk
+++ b/makefiles/include.mk
@@ -23,6 +23,10 @@
 MAKEDIR     ?= $(error MAKEDIR= is required)
 ONF_MAKEDIR ?= $(MAKEDIR)
 
+# Helpers -- eventually defined in lf/transition.mk
+onf-mk-dir   := $(MAKEDIR)
+sandbox-root ?= $(TOP)
+
 ## -----------------------------------------------------------------------
 ## -----------------------------------------------------------------------
 help::
@@ -32,9 +36,12 @@
 include $(MAKEDIR)/consts.mk
 include $(ONF_MAKEDIR)/utils/include.mk      # dependency-less helper macros
 include $(ONF_MAKEDIR)/etc/include.mk        # banner macros
+include $(ONF_MAKEDIR)/virtualenv/include.mk#  # python, lint, JJB dependency
 include $(MAKEDIR)/todo.mk
 include $(MAKEDIR)/lint/include.mk
 
+include $(MAKEDIR)/commands/pre-commit/include.mk
+
 $(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]