Add script to generate man pages from markdown

This is copied from docker

Signed-off-by: Mrunal Patel <mrunalp@gmail.com>

man/md2man-all.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+set -e
+
+# get into this script's directory
+cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
+
+[ "$1" = '-q' ] || {
+	set -x
+	pwd
+}
+
+for FILE in *.md; do
+	base="$(basename "$FILE")"
+	name="${base%.md}"
+	num="${name##*.}"
+	if [ -z "$num" -o "$name" = "$num" ]; then
+		# skip files that aren't of the format xxxx.N.md (like README.md)
+		continue
+	fi
+	mkdir -p "./man${num}"
+	go-md2man -in "$FILE" -out "./man${num}/${name}"
+done