fixup! Add certbot for managing a Lets Encrypt cert

cert_setup/docker-compose.yml

@@ -1,3 +1,12 @@
+# This Docker compose configuration sets up a temporary nginx server for use
+# when creating the initial set of certificates for Let's Encrypt.  This
+# container is created and destroyed by the init-certs.sh script and does not
+# need to be managed manually.
+#
+# 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