Say why the password step needs ssh -t

ansible/readme.md

@@ -72,10 +72,14 @@ Site:
 
 ```sh
 scp scripts/provision-site-env.sh monoco:/tmp/
-ssh monoco bash /tmp/provision-site-env.sh /var/lib/menu.hopsngrains.com
+ssh -t monoco bash /tmp/provision-site-env.sh /var/lib/menu.hopsngrains.com
 ssh monoco docker restart menu-app.hopsngrains.com
 ```
 
+The `-t` matters: the script prompts for the password, and without a terminal on
+the remote side the prompt cannot be read, so it would sit there looking frozen.
+With no image argument it borrows the one the running container uses.
+
 ## Rolling back
 
 Deploy the previous tag: