fixup! Add certbot for managing a Lets Encrypt cert

cert_setup/docker-compose.yml

@@ -1,3 +1,9 @@
+# This Docker compose configuration sets up a temporary nginx server
+# for use when creating the initial set of certificates for Let's Encrypt.
+# Since the certs have to exist before you can enable ssl mode in
+# nginx, we need a separate service set up in unencrypted mode to
+# do the initial verification from LE. Once the certs are created,
+# this service is torn down and not used again.
 services:
   nginx:
     image: nginx:1.27.3