Add Readme section about HTTPS

Readme.md

@@ -60,3 +60,47 @@ This fixes the causes of lint warnings (where possible).
 - MAIL_SERVER_BLACKLIST
   - list of domains, separated by comma
   - if the user tries to use such a mail service, then he will get the notification that this provider is not supported
+
+## HTTPS
+
+This server application itself does not support HTTPS. You have to use
+an other tool to use HTTPS. One options for this is to use nginx with the
+following site config:
+
+```
+# don't forget to update the port for your local configuration
+#
+# the max_fails is important - otherwise nginx
+# marks the server sometimes as unreachable if it is restarted
+# or starts after nginx
+upstream timelimitbackend {
+  server localhost:8080 max_fails=0;
+}
+
+server {
+  listen 443 ssl;
+  listen [::]:443 ssl;
+
+  # don't forget to update the domain
+  server_name my.domain;
+
+  # don't forget to update the paths
+  ssl_certificate /my/fullchain.pem;
+  ssl_certificate_key /my/privkey.pem;
+
+  # eventually configure the SSL parameters here
+
+  location / {
+    proxy_pass http://timelimitbackend/;
+
+    client_max_body_size 10m;
+    # the following is required for websocket support
+    #
+    # without websockets, the client will not detect
+    # that there is a connection and it will not sync
+    proxy_set_header Upgrade $http_upgrade;
+    proxy_set_header Connection "upgrade";
+    proxy_http_version 1.1;
+  }
+}
+```