doc: add a doc helper script

changed-docs.sh (and the accompanying awk script) shows docs changed
between a previous release branch and the current master branch, in a format that
can be used for the releae notes (a list of :ref: items).

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/scripts/changed-docs.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+# Create a reST :ref: list of changed documents for the release notes
+# comparing the specified tag with master branch
+#
+#
+
+if [ -z $1 ]; then
+   echo
+   echo Create a reST :ref: list of change documents for the release notes
+   echo comparing the specified tag with the master branch
+   echo
+   echo Usage:
+   echo \ \ changed-docs.sh upstream/release_3.0 [changed amount]
+   echo
+   echo \ \ where the optional [changed amount] \(default 10\) is the number
+   echo \ \ of lines added/modified/deleted before showing up in this report.
+   echo
+elif [ "$(basename $(pwd))" != "acrn-hypervisor" ]; then
+   echo
+   echo Script must be run in the acrn-hypervisor directory and not $(basename $(pwd))
+else
+    dir=`dirname $0`
+
+    git diff --stat `git rev-parse $1` `git rev-parse master` | \
+       grep \.rst | \
+       awk -v changes=$2 -f $dir/changed-docs.awk
+fi