doc/generate-changelog: add deis' changelog generation script

This file is under the Apache license

doc/generate-changelog.sh

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+usage() {
+    echo "Usage: $0 <from> [to]"
+}
+
+retrieve() {
+    git --no-pager log --oneline --pretty=format:" - %h %s" --no-merges --grep="$1" $FROM..$TO
+}
+
+subheading() {
+    echo "#### $1\n"
+    retrieve "$2"
+    echo
+    echo
+}
+
+FROM=$1
+TO=${2:-"HEAD"}
+
+if [ -z $1 ];
+then
+    usage
+    exit 1
+fi
+
+echo "### $FROM -> $TO\n"
+
+subheading "Protocol Adjustments" "protocol\/"
+subheading "Other Files" "etc\/"
+subheading "Documentation" "doc\/"
+subheading "Bot Commands" "bot\/"
+subheading "Core Improvements" "src\/"
+subheading "Core Modules" "core\/"
+subheading "Scrapers" "scrapers\/"
+subheading "Announcers" "announcer\/"
+subheading "Services" "services\/"