Add initial role for Dendrite as alternative Matrix server

roles/matrix-dendrite/templates/dendrite/usr-local-bin/matrix-dendrite-create-account.j2

@@ -0,0 +1,12 @@
+#jinja2: lstrip_blocks: "True"
+#!/bin/bash
+
+if [ $# -ne 2 ]; then
+	echo "Usage: "$0" <username> <password>"
+	exit 1
+fi
+
+user=$1
+password=$2
+
+docker exec matrix-dendrite create-account  --config /data/dendrite.yaml --user "$user" --password "$password"