Implement proper Cloudron structure with supervisor

supervisor/nginx.conf

@@ -0,0 +1,8 @@
+[program:nginx]
+command=nginx -g "daemon off;"
+autorestart=true
+stdout_logfile=/dev/stdout
+stdout_logfile_maxbytes=0
+stderr_logfile=/dev/stderr
+stderr_logfile_maxbytes=0
+user=root