Attempt at caddyfile/proxy, simplification

The idea of proxying in front of Garage may be warranted, to handle some
of the ways that it subdomains further. However, I'm not there yet.

README.md

@@ -123,6 +123,14 @@ make build DOMAIN=<domain>
 
 This runs `cloudron build`, and may (on first run) request a path to a registry. You can configure a private registry on your own Cloudron for this purpose. You need to pass the Cloudron domain here, so that the manifest can be set up correctly.
 
+For extended iteration
+
+```
+export DOMAIN=<domain>
+```
+
+will allow `make build ; make update` as a repeated sequence.
+
 
 ```
 <registry-domain>/<username>/<package-name>