docs: convert extras doc md->rst

Type: improvement

Change-Id: Ie3b25a86b99098d2b3a21a11fc73234c8ed589d6
Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
diff --git a/extras/scripts/check_documentation.sh b/extras/scripts/check_documentation.sh
new file mode 100755
index 0000000..2ab093d
--- /dev/null
+++ b/extras/scripts/check_documentation.sh
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+# Copyright (c) 2021 Cisco and/or its affiliates.
+# 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.
+
+set -eEo pipefail
+
+SCRIPTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+WS_ROOT=$( realpath ${SCRIPTDIR}/../.. )
+
+function red   () { printf "\e[0;31m$1\e[0m\n" ; }
+function green () { printf "\e[0;32m$1\e[0m\n" ; }
+
+find_linked_docs () {
+  find ${WS_ROOT}/docs -type l \
+      \( -name '*.rst' -o -name '*.md' \) \
+      -exec readlink -f {} \; | sort
+}
+
+find_excluded_docs () {
+    cat ${WS_ROOT}/docs/docsignore \
+      | grep -v '#' \
+      | sed s@^@${WS_ROOT}/@ \
+      | sort
+}
+
+find_linked_and_excluded_docs () {
+  cat <( find_linked_docs ) <( find_excluded_docs  ) | sort
+}
+
+find_candidate_docs () {
+  find \
+    ${WS_ROOT}/src \
+    ${WS_ROOT}/test \
+    ${WS_ROOT}/extras \
+    -not -path "${WS_ROOT}/test/venv/*" \
+    \( -name '*.rst' -o -name '*.md' \) \
+    | sort
+}
+
+spellcheck () {
+    make -C ${WS_ROOT} docs-spell
+}
+
+if [ "x$(comm -13 <( find_linked_and_excluded_docs ) <( find_candidate_docs ))" != x ]; then
+    red "The following files need to be linked"
+    red "in the doc folder e.g. :"
+    red "$ cd vpp/docs/developer/plugins"
+    red "$ ln -s ../../../src/plugins/my_plugin/my_plugin.rst"
+    echo ""
+    cat <( comm -13 <( find_linked_and_excluded_docs ) <( find_candidate_docs ) )
+    exit 1
+fi
+spellcheck
+green "**********************************************"
+green "* VPP Docs Checkstyle Successfully Completed *"
+green "**********************************************"