feat: Add dockerize to the Dex docker image

Signed-off-by: m.nabokikh <maksim.nabokikh@flant.com>

entrypoint.sh

@@ -0,0 +1,11 @@
+#!/bin/sh -e
+
+### Usage: /entrypoint.sh <command> <args>
+command=$1
+
+if [ "$command" == "serve" ]; then
+  file="$2"
+  dockerize -template "$file" | dex serve -
+else
+  dex $@
+fi