[DEPLOY] Update deployment files for new database

deploy/example.env

@@ -2,6 +2,10 @@
 # Used to generate CSRF tokens - must never be made public
 SECRET_KEY=changeme
 
+# REQUIRED=Database password
+# The password for the breccia-mapper user in the postgres database
+DB_PASSWORD=changeme
+
 # Debug
 # Should the server run in debug mode?  Provides information to users which is unsafe in production
 # Default: False