Add entry point

Stalwart/resources/docker/entrypoint.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env sh
+# this file was taken directly from the stalwart entry point.sh
+
+# check if there is a config already
+if [ ! -f /opt/stalwart/etc/config.toml ]; then
+    # if not then make a new one
+    /usr/local/bin/stalwart --init /opt/stalwart
+fi
+
+# if there is a config run the old one
+exec /usr/local/bin/stalwart --config /opt/stalwart/etc/config.toml