add quotation marks

README.md

@@ -127,7 +127,7 @@ On the `pg_hba.conf` file add a line like that at the end:
 host    all             all             <the netmask you want to add>            scram-sha-256
 ```
 
-Also change the `listen_addresses` instruction to `*` in `postgresql.conf`.
+Also change the `listen_addresses` instruction to `'*'` in `postgresql.conf`.
 
 ## Install Nginx