VOL-4840 - docs.voltha.org edits

Makefile
patches/python_310_migration.sh
-------------------------------
   o Change log message to note venv patching by version.
   o Original message could be interpreted as explict patching of wrong version.

makefiles/lint/include.mk
-------------------------
   o Document lint targets: usage, commands, makefiles, etc.

Change-Id: I895a0a032f856632c9adf31aa634b6cbf0328cdb
diff --git a/makefiles/lint/shell.mk b/makefiles/lint/shell.mk
new file mode 100644
index 0000000..da92921
--- /dev/null
+++ b/makefiles/lint/shell.mk
@@ -0,0 +1,33 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2022 Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+
+JSON_FILES ?= $(error JSON_FILES= is required)
+
+.PHONY: lint-shell
+
+lint : lint-shell
+
+lint-shell:
+	shellcheck --version
+	find . \( -name 'staging' -o -name 'vst_venv' \) -prune \
+	    -o -name '*.sh' ! -name 'activate.sh' -print0 \
+	| xargs -0 -n1 shellcheck
+
+help::
+	@echo "  lint-shell           Syntax check bash,bourne,etc sources"
+
+# [EOF]